If your cat's phosphorus level (in blood tests) is over
6
mg/dl (USA) or over 1.9 mmol/L (international),
it is too high and you need to get it under control.
In some cases you should
take action sooner (see
The Importance of
Phosphorus Control).
Keeping phosphorus levels under control can help slow the progression of the CKD,
reduce the risk of serious problems and make your cat feel better.
Feeding a food low in phosphorus is the first and best step.
Ideally you want a food with a level below 0.5% phosphorus on a
dry
matter analysis (DMA) basis. Therapeutic kidney diet foods are the only complete foods which
meet this criterion.
If your cat will not eat a therapeutic kidney diet, feeding
a food as low in phosphorus as possible and adding
a phosphorus binder to the food when appropriate can help control your cat's phosphorus
levels.
This page explains all you need to know about
phosphorus binders.
On the left is a list of this page's contents.
Why
High Phosphorus Levels Matter
Phosphorus is a mineral essential for good health which
is contained in many foods. The body is very good at regulating its
phosphorus levels by removing excess phosphorus via the kidneys. However,
the kidneys of a CKD cat can no longer
efficiently excrete excess phosphorus, so the vast
majority of CKD cats will develop
levels of phosphorus in their blood which are too high:
this is known as
hyperphosphataemia.
In contrast to the
protein debate, there is no
dispute about the importance of treating
hyperphosphataemia because of the problems it causes. Indeed, an update on
the
Western Veterinary Conference 2017
reports on a presentation to the conference by Dr D Chew and states that "phosphorus restriction may be the "single most
powerful treatment," according to Dr. Chew."
High phosphorus levels may:
make
the cat feel unwell
cause
CKD progression
cause an unpleasant complication of CKD
called secondary hyperparathyroidism
The first line of
phosphorus control is to feed foods low in phosphorus, ideally a therapeutic
kidney diet.
Survival of cats with naturally occurring chronic
renal failure: effect of dietary management (2000) Elliott J,
Rawlings JM, Markwell PJ, Barber PJ Journal of Small Animal Practice41(6) pp235-242 found that feeding a reduced phosphorus therapeutic
kidney diet provided
effective phosphorus control in two thirds of the cats in Stage 2 and 3
CKD. In addition, the cats eating the therapeutic kidney diet lived more than
twice as long as the cats in the study who ate normal food with no phosphorus
binder.
Controlling Phosphorus Levels with Phosphorus
Binders
If your cat will not eat a therapeutic kidney diet, or
if his/her phosphorus levels are still too high (see The
Importance of Phosphorus Control) despite
feeding such a diet for a month, products called phosphorus binders are
used.
Even if your cat is eating a low phosphorus diet, at
some point it is quite possible that this will become insufficient to
control your cat's phosphorus levels.
The role of phosphorus in feline chronic renal
disease (2010) Chew D & Kidder ACVC in San Diego Proceedings states "Diet
alone is not successful in adequate phosphorus control as chronic renal
disease becomes more advanced. In these instances serum phosphorus
concentration increases above the normal range or stays in the upper half
of the normal range."
Phosphorus binders work by binding with some of the phosphorus in the
cat's food in the intestine, which is then passed out in the stool. This prevents the
phosphorus in the food from being absorbed into the bloodstream, and
therefore over time this reduces the levels of phosphorus in the cat's body.
To be effective, phosphorus binders must be given shortly before or,
preferably, with food. You should start to see a difference
in your cat's blood phosphorus levels around 7-10 days after starting binders. There
are instructions on how to give binders below.
Using binders is not as effective as feeding a
therapeutic kidney diet, because binders cannot bind all the phosphorus in the
food, so your cat will still be absorbing some of the phosphorus in the
food. Therefore, if you do have to feed a non-therapeutic kidney food
with a higher phosphorus content than is ideal (because
the most important thing is that your cat eats), you should still aim to
feed the lowest phosphorus food that your cat will eat. The
Cat Food Data
chapter has links to food data tables for you to check out the
phosphorus levels of over 1500 cat foods in the USA. I am not
recommending any of these foods, this is simply a list in order of
phosphorus content.
Survey of dietary and medication practices of owners
of cats with chronic kidney disease
(2014) Markovich JE, Freeman LM, Labato MA and Heize CR Journal
of Feline Medicine and Surgery22 found that only 22% of the
1080 cats in the survey were receiving phosphorus binders. Not all of the
cats may have required binders at the time of the survey but this is still
a very low percentage considering the consequences of not controlling
phosphorus levels in CKD. So if your vet does not offer you phosphorus
binders, do not assume you do not need them, ask for your cat's phosphorus
levels and take action if your cat's levels are too high.
When to Start Phosphorus Binders
You should not normally need to use binders if your cat
is eating a therapeutic kidney diet, at least in the early stages of CKD,
because the therapeutic diet should be sufficient to control your cat's
phosphorus levels. However, this is not always the case, particularly as
the CKD worsens.
The role of phosphorus in feline chronic renal
disease (2010) Chew D & Kidder AC
CVC in San Diego Proceedings says
"Intestinal phosphate binders should be added if serum phosphate remains
increased after one month of consuming the renal diet or if the switch to
the renal diet is not accepted by the animal."
Please see
The
Importance of Phosphorus Control: to learn when
you may need to start using binders and discuss this with your vet.
Remember, a phosphorus level within normal range is not sufficient for a
CKD cat.
If your cat isn't eating at all, there is little point
giving phosphorus binders because your cat isn't ingesting any phosphorus
in
food that needs binding. However, if you
assist feed (as you should if
your cat is not eating), you can add binders to the food you are feeding if necessary (although this
may not be necessary if you are assist feeding a therapeutic kidney diet).
Types of Phosphorus Binder
There are a large number of phosphorus binders
available, which I have divided into the following categories based upon the primary binding ingredient:
Only three types are commonly used in cats: aluminium hydroxide, calcium
carbonate and lanthanum carbonate, though there is growing interest in the
use of niacinamide. Most people on Tanya's CKD Support Group use
aluminium-based products.
Many of these products are available as simple over the counter antacids, but branded
products are also available. All types have pros and cons.
Aluminium-Based
Binders
There are three main types of aluminium-based binders, but
aluminium hydroxide is generally considered to be the best choice within this
family of medications.
This type of binder, as the name suggests, also contains magnesium.
These products are commonly sold as antacids (but are not the best choice
for that purpose for CKD cats).
Brand names include Maalox, Mylanta, Milk of
Magnesia or Aludrox.
Binders containing magnesium are not suitable for
CKD cats because they
can cause
high
magnesium levels in the blood, which in turn may cause
urinary tract problems such as stones in some cats.
PetCoach
states "Do not use magnesium containing products in
animals with kidney failure."
Therefore a vet may occasionally
also recommend sucralfate
as a phosphorus binder,
but it is not a good choice for cats.
Evaluating sucralfate as a phosphate binder in
normal cats and cats with chronic kidney disease
(2016) Quimby JM & Lappin M Journal of the American Animal
Hospital Association52(1) pp8-12 evaluated sucralfate's
efficacy as a phosphorus binder in healthy cats and in CKD cats with
phosphorus in the normal range. There was no change in phosphorus levels
in the healthy cats, but 14.7% of them vomited after being given it. The
CKD cats given sucralfate did not show reduced phosphorus levels but sixty
percent (three cats out of five) exhibited vomiting, anorexia and elevated
BUN and creatinine levels, to such a degree that the study was
discontinued. If your vet prescribes sucralfate, I would show them this
study.
If you are using sucralfate for mouth ulcers or
gastrointestinal bleeding at the same time as using aluminium hydroxide
as a phosphorus binder, you might possibly be able to reduce your dosage
of aluminium hydroxide, though this is not a given based on the results of
the above study.
Aluminium Hydroxide
Aluminium hydroxide, Al(OH)3, is the best choice of the aluminium-based binders. Its
advantages are that it is effective, odourless and tasteless (if you buy
the correct type), available over the counter (though you will have to use
a local compounding pharmacy or mail order in the USA if you want the
odourless and tasteless type) and relatively cheap.
Aluminium hydroxide is apparently no longer available
in Germany. Members of the German nierenkranke Katze Support Group are
therefore using aluminium oxide instead.
Many vets are reluctant to prescribe aluminium-based binders because they
think cats
hate the taste. This may be because many vets seem to
only be familiar with
AlternaGel, a
peppermint-flavoured aluminium hydroxide binder which most cats
hate, so it then becomes a self-fulfilling
prophecy. AlternaGel also contains
potassium citrate, which is
not a good idea because citrate can increase the absorption of aluminium
within the body.
Odourless and Tasteless Powder, Including Phos-Bind
Fortunately, there are alternatives, including tasteless and odourless
powder varieties which
most cats do not seem to notice in their food, although recently people
have commented that the powders appear to be coarser.
Thriving
Pets sells one such product. Their product is around 85% pure (no
aluminium hydroxide product will be 100% pure because it is a natural
mined product).
Phos-Bind is a newer brand of loose aluminium
hydroxide binder made by Rx Vitamins. Phos-Bind is around 77% pure.
You may also be able to obtain powdered aluminium hydroxide from your
local compounding pharmacy.
If you look around on eBay etc, be very careful because you need
pharmaceutical grade aluminium hydroxide, and many products available on
auction sites are
not pure enough and not suitable for CKD cats.
See
below for information on the various brands and
where to buy them, including links to mail order suppliers who can ship to
the UK, USA,
Canada and Australia. Contrary to what some vets and pharmacists seem to believe,
you do not need a prescription to buy these products.
ConSeal-AlH
Chews
ConSeal-AlH are aluminium
hydroxide 200 mg chews made by Bock Pharma which some vets in the USA are
beginning to stock. They come in a box of 28
individually wrapped chews. The chews are semi-soft
so can be broken or cut into pieces. In this form they can be mixed with
food, but one member of
Tanya's CKD Support Group
found the chews very helpful for her cat who missed getting
treats, and gave them before her cat's meals. They could also be useful
for multi-cat households where you can give your CKD cat a ConSeal treat
whilst giving your other cats ordinary treats.
Aluminium Hydroxide Dosage Recommendations
Unfortunately, there is no one perfect dosing schedule: it depends upon
your cat's phosphorus level, stage of CKD, the type of food your cat eats
and how well s/he responds to binders.
Therefore there are a number of recommended dosage protocols, which fall into three
categories:
ISFM and Dr Chew simply give a dosage range.
Dr Nagode's recommended dosage varies depending upon your cat's current
phosphorus level.
The IRIS recommendations look at both your cat's existing phosphorus level
and your cat's creatinine level. This is because IRIS accepts that the
more advanced the CKD is (as indicated by the creatinine level), the harder it can be to
reduce your cat's phosphorus levels.
It is usually best to start at the lower recommended levels, increasing
the dose only if your cat's blood phosphorus levels do not reduce, but be
guided by your vet.
states "initially
is used at a dosage of 20-30 mg/kg q8h or 30-45 mg/kg q12h given with
food."
That is a
total of 60-90 mg/kg a day.
Dr Larry Nagode, formerly of Ohio State University College of
Veterinary Medicine
The following dosages were provided by Dr Larry Nagode, formerly of
Ohio State University College of Veterinary Medicine, now sadly
deceased.
USA
Current Phosphorus Level: mg/dl
Binder Dosage
Between 4.0 and 6.00
25 mg per lb of cat per day
Between 6.0 and 8.0
50 mg per lb of cat per day
Between 8.00 and 10.00
100 mg per lb of cat per day*
Over 10.00
Discuss with your vet*
International
Current Phosphorus Level: µmol/L
Binder
Dosage
Between 1.3 and 1.9
50 mg per kg of cat per day
Between 1.9 and 2.6
100 mg per kg of cat per day
Between 2.6 and 3.25
200 mg per kg of cat per day*
Over 3.25
Discuss with your vet*
*I would not give more than 50 mg per lb of cat per
day (100 mg per kg of cat per day) without detailed discussions with your
vet. It is probably safe, but you need to balance the potential benefits
against the possible risks, including the rare possibility of aluminium
toxicity - see below.
If your cat needs large amounts of binder, it may be safer to use a smaller amount of aluminium hydroxide together
with another binder, such as
lanthanum carbonate (Renalzin or Fosrenol).
The
International Renal Interest Society (IRIS)
Treatment recommendations for CKD in cats
(2019)International Renal Interest Society
recommends using binders if phosphorus levels are as shown in the tables
despite dietary restriction of phosphorus:
USA
Stage of CKD
Creatinine Level (mg/dl)
Current
Phosphorus Level mg/dl
Binder Dosage
IRIS Stage 2
Between
1.6 and 2.8
Above 4.6
14-28 mg per lb of cat per day
IRIS Stage 3
Between 2.9
and 5.0
Above 5.0
14-28 mg per lb of cat per day
IRIS Stage 4
Over 5.0
Above 6.0
14-28 mg per lb of cat per day
International
Stage of CKD
Creatinine Level (mmol/L)
Current
Phosphorus Level (mmol/l)
Binder Dosage
IRIS Stage 2
Between
140 and 249
Above 1.5
30-60 mg per kg of cat per day
IRIS Stage 3
Between 250
and 439
Above 1.6
30-60 mg per kg of cat per day
IRIS Stage 4
Over 440
Above 1.9
30-60
mg per kg of cat per day
As you
can see, the IRIS recommended amounts of binder are actually the
same for every stage. What is different is:
when they suggest that you try to control high phosphorus levels. For example, for
a cat in IRIS Stage 2 you would treat a phosphorus level
above 4.6 mg/dl or 1.5 mmol/L international, whereas, for a cat in
Stage 3, a level above 4.6 mg/dl (1.6 mmol/L international) would be
acceptable as long as it was no higher than 5 mg/dl (1.9 mmol/L
international).
the target phosphorus level for each stage of CKD. Basically you
want it below the level at which you start binders, so for example,
for a cat in Stage 2 you want the phosphorus level to be below 4.6 mg/dl
or 1.5 mmol/L international. See
Aluminium Hydroxide Dosage Calculations and Adjustments
I expect your head is spinning now! I know quite a few people get confused
by all these recommended dosages, so here is a summary, along with some
tips on how to choose or adjust the dosage.
Recommendation
Cat Weight
Source
Total
Daily Dosage
per kg of
cat*
5 lb
2.27 kg
7.5 lbs
3.4 kg
10 lb
4.5 kg
12.5 lbs
5.7kg
IRIS
30-60 mg
68-136 mg
102-204 mg
135-270 mg
170 - 340 mg
Dr Chew
60-90 mg
136-204 mg
204-306 mg
270-405 mg
340 - 513 mg
ISFM**
90 mg
204 mg
306 mg
405 mg
513 mg
Dr Nagode
50-200 mg
113-450 mg
170-680 mg
225-900mg
285 - 1140 mg
Total Range
30-200 mg
68-450 mg
102-680 mg
135-900mg
170 - 1140 mg
*A kg is 2.2 lbs
**These are starting dosages, and can be increased if they are not
sufficient to reduce
your cat's blood phosphorus levels
Remember, the amounts given are the total daily dosage.
The total amount should be divided among as many of your cat's daily meals
as possible, ideally with larger meals receiving a larger proportion of
the daily dose (see Mixing with Food below).
See
below for how to
give binders, including how to mix them with your cat's food.
Aluminium Hydroxide: Choosing a Dosage
The
ranges for how much to give are quite wide, so talk to your vet
about a suitable starting point for your cat. Many people successfully
follow Dr Nagode's recommendations
above, though these tend
to be higher than those of other experts, because recently there is a trend to be
more cautious with dosing in order to reduce the risk of
aluminium toxicity.
Taking
all the experts' recommendations above, here is what I would
probably try myself. However, this is just my opinion, and if your
vet recommends a different dosage regimen, you should of course
follow your vet's advice:
Cat's Phosphorus Level mg/dl
Cat's Phosphorus Level
mmol/L
Possible Starting Daily Dose
Below 6
Below 1.9
30 mg per kg of cat
14 mg
per lb of cat
Between 6 and 7
Between 1.9 and 2.25
60 mg
per kg of cat
27 mg
per lb of cat
Above 7
Above 2.25
90 mg
per kg of cat
40 mg
per lb of cat
Aluminium Hydroxide: Adjusting a Dosage
Your
cat's blood phosphorus levels should start falling 7-10 days after
starting a phosphorus binder. Your vet should check your cat's blood
phosphorus levels 10-14 days after starting a binder. If your cat's
blood phosphorus level is not falling, you should discuss increasing the dose
you are using with your vet. If the phosphorus level seems to be
falling, I would continue with the dosage you are using.
I am
often asked if you should stop using a binder or adjust the dosage
once your cat's blood phosphorus has fallen to a satisfactory level.
Normally you will need to continue with the binder. In most cases,
you will need to continue with the dosage that reduced your cat's
blood phosphorus levels to your target level, but you can of course
speak to your vet about adjusting the dose, either upwards or
downwards, if necessary, e.g. if your cat's CKD starts to worsen and
phosphorus levels start to rise again.
Aluminium hydroxide does not have to be measured
too precisely, but as a rough guide:
Form of Aluminium Hydroxide
Amount
Contains approximately
Thriving Pets (powdered) and some
compounding pharmacies
Half a teaspoon, loosely packed
600 mg
Phos-Bind* 200g (powdered):
One level scoop (scoop comes with
the product and contains around half a teaspoon)
500-600 mg
Phos-Bind*
35g (powdered)
One level scoop (scoop comes with
the product and contains around a quarter of a teaspoon)
250-320 mg
Hyperdrug UK (powdered)
One level scoop
(scoop comes with the product and contains around 0.5ml, which seems
very low)
650 mg
Pets Drug Mart Canada (powdered)
One level scoop (scoop
comes with the product and contains around a teaspoon)
1200 mg
Liquid e.g. AlternaGel
One teaspoon
600 mg
*Please note the Phos-Bind scoop size varies,
with the scoop that comes with the 35g size apparently holding
approximately half as much as the scoop that comes with the 200g size.
I used to have the following table on the website, and
have received so many requests for it that I am including it again. Please
note that:
these calculations apply to the powdered form sold by
Thriving Pets, not to Phos-Bind.
the amounts involved are so tiny that I have had to do
quite a bit of rounding up or down.
Thriving Pets AlOH
Cat Weight
Source
Total
Daily Dosage
per kg
5 lb
2.27 kg
7.5 lbs
3.4 kg
10 lb
4.5 kg
12.5 lbs
5.7kg
Dosage
mg
Dosage tsp
Dosage mg
Dosage tsp
Dosage mg
Dosage tsp
Dosage mg
Dosage tsp
IRIS
30-60 mg
68-135
1/16-1/9
102-204
1/12-1/6
135-270
1/8-1/4
170-340
1/8-1/4
Dr Chew
60-90 mg
135-204
1/9-1/6
204-306
1/6-1/4
270-405
1/4-1/3
340-513
1/4-2/5
ISFM*
90
204
1/6
306
1/4
405
1/3
513
2/5
Dr Nagode**
50-200 mg
113-450
1/9-3/8
170-680
1/8-1/2
225-900
1/6-3/4
285-1140
1/4-1.0
Total Range
30-200 mg
68-450
1/16-3/8
102-680
1/12-1/2
135-900
1/8-3/4
170-1140
3/4-1.0
* Starting dose
** Dr Nagode's recommendations vary depending upon the cat's initial blood
phosphorus level
Yep, these numbers are tiny and fiddly. I recommend that rather than
guessing and trying to measure tiny quantities, you buy a set of measuring
spoons which include a pinch (I think this may
be 1/16th), 1/8, 1/4, 1/2, 2/3 and 1 tsp for less than USD15 from
Amazon.
The same set costs under £12 from
Amazon UK. If you buy these, you can
simply scoop out the amount you need each day using the appropriate spoon.
If you can't get the spoons and need to measure it yourself, try this:
take a standard-sized teaspoon (the standard-sized teaspoon typically holds 5ml
of liquid).
Fill your teaspoon with aluminium hydroxide powder.
Then empty onto a dish and divide it as needed. For
example, if you are giving a quarter of a teaspoon (¼ of a tsp) a day,
divide your teaspoon of aluminium hydroxide which you have poured onto a
dish into
four. You would then have four days worth of aluminium hydroxide treatment
on your dish.
If you look at the numbers above, you can see how many piles to divide
into. So for three eighths, divide it into eight and you would use three
of the eight portions. For one sixth, divide into six and use one portion
per day; and so on.
Remember, you won't give your daily dosage all in go. You will divide it
between all your cat's meals on that day.
How and When to Give Aluminium Hydroxide
Aluminium hydroxide must be given with food so they can bind with the
phosphorus in it. See below
for how to give binders.
Aluminium Hydroxide Side Effects
Sometimes aluminium hydroxide-based binders may cause
constipation,
so watch for this when you first start them and be
ready to start a suitable
treatment
if required.
Please see
below for more
information on
aluminium toxicity.
Aluminium
Hydroxide Interactions
Potassium Citrate
As
Prescribers' Digital Reference mentions, products containing
citrate may increase the absorption of aluminium,
which could increase the risk of
aluminium toxicity
(though apparently these findings have not been
replicated in cats). The most commonly used citrate-containing products in
CKD cats are potassium
citrate (perhaps to treat
metabolic acidosis), and many therapeutic kidney diets.
If you are using potassium citrate, give this at least two hours apart from
aluminium-based
binders.
It is trickier to juggle aluminium hydroxide and
therapeutic kidney diets
because aluminium hydroxide binders of course need to be given with food. You will probably not need to use phosphorus binders if you are
using a therapeutic kidney diet, at least in early to mid stage CKD, but if you
do have to use both, check the therapeutic kidney food you are feeding to see if
it contains potassium citrate (other forms of potassium are not a problem)
and consider switching to another therapeutic kidney food which does not contain
potassium citrate. It might also be worth switching to another type of
phosphorus binder, either completely or by mixing aluminium hydroxide with
foods not containing potassium citrate and adding another binder to foods
which do contain potassium citrate. Speak to your vet about the best way forward.
"Due to
varying effects of intestinal phosphate binders to limit absorption of
drugs, it is advisable to give other drugs 1 hour before or 3 hours after
any intestinal phosphate binder is given."
Plumb's also recommends separating aluminium hydroxide
from
corticosteroids.
Aluminium hydroxide should ideally be given separately from oral
iron
supplements
because the aluminium hydroxide may reduce the absorption of the iron.
Plumb's Veterinary Drug Handbook also advises
giving aluminium hydroxide two hours apart fromfamotidine
(Pepcid AC), which is used to treat
excess stomach acid, because it may interfere with the absorption
of the treatment, which would make it less effective.
However,
RX Med states that "concomitant use of
aluminum hydroxide/magnesium hydroxide at commonly used doses, does not
influence the pharmacodynamics or bioavailability of Pepcid AC."
I would try to err on the side of caution and still
separate famotidine from phosphorus binders and ACE inhibitors if you can,
but if this is difficult for you, e.g. because of work commitments, just
do the best you can.
Aluminium hydroxide binders should be given two hours apart from
ACE
inhibitors,
because the binder may reduce the bioavailability of the ACE inhibitors.
Drugs has more information about this.
Pennstate Hershey
mentions that
vitamin C may interact adversely with products containing aluminium,
such as phosphorus binders. Cats do not need vitamin C
supplements anyway, because their bodies can manufacture all the Vitamin C
they need.
I don't know if
slippery elm
bark would interfere with aluminium hydroxide, as far as I know this
has never been studied, but it might be possible in theory. However, if
you are adding slippery elm bark to food once or twice a day, I would
still mix binders in with that food in the hope that at least some of the
phosphorus would be bound.
(2011) Mudge DW, Johnson DW, Hawlet CM, Campbell SB,
Isbel NM, van Eps CL & Petrie JJB Nephrology12
states "Available historical evidence however, suggests that neurological toxicity
may have primarily been caused by excessive exposure to aluminium in
dialysis fluid, rather than aluminium-containing oral phosphate binders.
Limited evidence suggests that aluminium bone disease may also be on the
decline in the era of aluminium removal from dialysis fluid, even with
continued use of aluminium binders...The relative contribution of aluminium binders to aluminium toxicity would
appear to be minor based on the available evidence."
Do oral aluminium phosphate binders cause
accumulation of aluminium to toxic levels?
(2011) Pepper R, Campbell N, Yaqoob MM, Roberts NB &
Fan SLS BMC Nephrology12 found that even patients on
dialysis did not develop aluminium toxicity if changes were made to the
dialysis process (during which patients may be exposed to dialysate water
which is contaminated with aluminium), but the patients in this study were
on relatively low doses of aluminium hydroxide.
Since cats are not normally on dialysis, aluminium toxicity was not
thought to be a
concern for cats (or dogs), especially since even in humans it takes
years before it becomes a problem, and cats and
dogs don't live as long as humans.
Recently, however, there has been increasing concern
about the possible risk of aluminium toxicity in cats using aluminium
hydroxide based binders. This is partly because of a study which reported
on aluminium toxicity in two dogs on binders,
Aluminum toxicity following administration of
aluminum-based phosphate binders in 2 dogs with renal failure(2008)
Segev G,
Bandt C,
Francey T &
Cowgill LDJournal of Veterinary
Internal Medicine22(6) pp1432-5.
There is no abstract available for this study, but
Treatment options for hyperphosphataemia in feline
CKD: what's out there? (2009)
Kidder AC & Chew D Journal of Feline Medicine & Surgery11(11)
pp813-24 reported that the two dogs in question developed "probable
aluminum toxicity" after being on binders for only 62 and 65 days. The
symptoms seen were "severe neuromuscular abnormalities." The dogs were on
dosages of 125mg/kg per day (or 56mg per lb body weight) and 200 mg/kg (or
91mg per lb bodyweight) per day, which are not particularly high doses.
However, both these dogs had been on dialysis, though apparently the
dialysate water was not contaminated with aluminium.
Partly because of this study, vets are
becoming increasingly aware of the need for caution and awareness when
using aluminium hydroxide binders in cats too, particularly when using
large doses.
Chronic kidney disease (CKD) in dogs and cats — staging and management
strategies (2015) Chew D
Presentation to the Virginia Veterinary Medical Association 2015 Virginia
Veterinary Conference says "THERE IS NO KNOWN SAFE DOSE OF ALUMINUM SALTS FOR HUMANS WITH CKD.
Detrimental effects of aluminum based phosphate binders as described in
humans seen in humans have not been systematically evaluated in small
animal patients and are rarely clinically appreciated. As cats with CKD
can live for years on treatment, concerns for aluminum accumulation
deserve more study as to long-term safety."
Physical symptoms to watch for include muscle weakness
or neurological
problems, such as stumbling and an awkward gait (although, just to
complicate matters, these can actually be signs of uncontrolled
phosphorus levels too, see
above). One possible
early sign of aluminium toxicity is a change in
MCV.
This is a measure of red blood cell size.
If your cat has a low MCV (known as microcytosis),
this means the red blood cells are smaller than usual.
Although this may simply indicate iron deficiency, it may also be a sign
of aluminium toxicity. This sign normally appears before you see physical
symptoms, so be sure to monitor your cat's MCV levels.
If you are using
potassium
citrate (perhaps to treat
metabolic acidosis), give this at least two hours apart from phosphorus
binders. This is because, as
Prescribers' Digital Reference explains, products containing
citrate can in theory increase the absorption of aluminium,
which could increase the risk of aluminium toxicity.Many
therapeutic kidney
diets contain potassium citrate. See
above for more
information on aluminium hydroxide and potassium citrate.
Try not to worry too
much. I am only aware of one case of
aluminium hydroxide toxicity in cats to date (this cat was given massive
doses of aluminium hydroxide, more than twice as much as she would
normally be given based upon Dr Nagode's protocol
above), and most cases in
dogs have occurred in dogs taking over 200 mg/kg.
Updates in feline chronic kidney disease
(2008) Langston CL states "Excessive absorption of aluminum can
lead to toxicity, including anemia and neurologic symptoms, but this seems
uncommon in veterinary practice." In contrast, the
dangers of elevated phosphorus control are very real, and very common, and
controlling phosphorus is essential for your cat's wellbeing.
If your cat has phosphorus levels that require large
amounts of aluminium hydroxide, or if you cannot control your cat's
phosphorus levels with aluminium hydroxide only, consider adding another
phosphorus binder. Most people in this situation use lanthanumcarbonate (Renalzin or Fosrenol).
See below
for suggestions on dosage.
If you think your cat may have aluminium toxicity, I
would ask for a referral to a vet school or a neurologist if possible.
Chelation therapy plus dialysis helped to remove the aluminium from dogs with aluminium
toxicity, and indeed following treatment the neurological problems
experienced by the dogs in the above study were successfully reversed.
Aluminium Studies
Ohio State University College of Veterinary Medicine is running a trial into aluminium
levels in healthy and CKD cats. You can read more about it on the
Feline Research
page.
Ohio State University College of Veterinary Medicine
is also running a trial into the
effect of aluminium food cans on cats with kidney disease.
This is also discussed on the Feline Research
page.
Aluminium Hydroxide: Other Concerns
If you buy aluminium hydroxide gel or powder in the
USA, you may see a warning about arsenic which bizarrely
supposedly only applies to people living in California. This is to
comply with that state's legal requirements. The fact is
that aluminium hydroxide is a naturally occurring product which is
mined, and therefore it contains a naturally occurring tiny amount of
arsenic of no more than 8 parts per million. This is no more than you
might find in soil or in vegetables grown in soil. However, if you want
to be on the safe side, you might wish to avoid inhaling the powder.
In some cases when buying aluminium hydroxide, you may see an
expiration date on it. This is usually to comply with pharmacy laws, but
in practice, since aluminium hydroxide is a mineral that is mined from the
earth, it cannot really expire, so if you are using a gel or powder form
of aluminium hydroxide, I would not worry too much about expiry
dates. However, if you are using a suspension of some kind, it may expire
because of other ingredients in the mix.
Lanthanum Carbonate
Lanthanum carbonate is a newer type of phosphorus binder.
Like aluminium hydroxide, it appears to be tasteless and
Pharmacology of the phosphate binder, lanthanum
carbonate (2011) Damment SJP Renal Failure33(2) pp217–224 found that lanthanum carbonate-based binders appear
to be as effective as aluminium hydroxide-based binders.
Nefrokrill is an Italian product for cats that may become more widely
available.
Renalzin was designed for cats but sadly has been discontinued so is virtually
impossible
hard to find.
Renalan, a lanthanum-based
phosphorus binder, was undergoing testing on cats and was reported to be seeking regulatory approval
in 2008 but it seems to have disappeared.
Therefore your only choices will be
Fosrenol or Nefrokrill.
Fosrenol is
the human version of
lanthanum carbonate which has been
available in the USA
since 2005 and is gradually
being used in cats. A prescription is required.
Fosrenol
comes in the form of extremely expensive tabletswhich are supposed to be chewed,
but in order to use them for cats, most people crush
the tablets. In 2015 a powder form was released.
In humans this is supposed to be mixed with apple sauce
or similar but I imagine you could simply add it to your cat's food.
Eurek Alert
has a press release regarding the approval process for Fosrenol in the
USA.
Nefrokrill
Nefrokrill is a product from Italy that
may also be available in other parts of Europe. It comes in small
capsules (which they call pearls), and each contains a combination of:
lanthanum carbonate (280mg)
essential fatty acids (EPA 140 mg, DHA100 mg and vitamin E 20mg,
with additional krill oil of 50mg)
It costs around €43.40 for 60 pearls or €29.40 for 30.
Nefrokrill would not be suitable if your cat has high potassium levels.
Please also read up on
krill oil.
Lanthanum Carbonate Dosage Recommendations
Fosrenol dosing is the same as for aluminium hydroxide.
So, for example, if you are giving 300mg of aluminium hydroxide a day but
want to switch to Fosrenol, you would still need to give 300mg per day.
Having said that, there are a number of recommended dosage
protocols, as follows:
states "doses of 35 mg/kg/day to 50 mg/kg/day are often needed
since commercial cat foods contain more phosphate proportionally than what
an average human consumes daily. A recent abstract in a small number of
CKD cats administered lanthanum carbonate in food at 95 mg/kg/day to
achieve very modest serum phosphate control (Pressler ACVIM 2013)."
The
International Renal Interest Society
Treatment recommendations for CKD in cats
(2019)International Renal Interest Society
recommends a staged approach to phosphorus control, as shown in the tables
below. It recommends using binders if phosphorus levels are as shown in
the tables despite dietary restriction of phosphorus.
USA
Stage of CKD
Creatinine Level (mg/dl)
Current
Phosphorus Level mg/dl
Binder Dosage
IRIS Stage 2
Between
1.6 and 2.8
Above 4.6
14-28 mg per lb of cat per day
IRIS Stage 3
Between 2.9
and 5.0
Above 5.0
14-28 mg per lb of cat per day
IRIS Stage 4
Over 5.0
Above 6.0
14-28 mg per lb of cat per day
International
Stage of CKD
Creatinine Level (mmol/L)
Current
Phosphorus Level mmol/L
Binder Dosage
IRIS Stage 2
Between
140 and 249
Above 1.5
30-60 mg per kg of cat per day
IRIS Stage 3
Between 250
and 439
Above 1.6
30-60 mg per kg of cat per day
IRIS Stage 4
Over 440
Above 1.9
30-60
mg per kg of cat per day
As you
can see, the recommended amounts of binder are actually the same for
each stage. What is different is:
firstly,
when you start treating for high phosphorus levels. For example, for
a cat in IRIS Stage 2 you would start treating a phosphorus level
above 4.6 mg/dl or 1.5 mmol/L international, whereas for a cat in
Stage 3 a level above 4.6 mg/dl (1.6 mmol/L international) would be
acceptable as long as it was no higher than 5 mg/dl (1.9 mmol/L
international).
secondly,
the target phosphorus level for each stage of CKD. Basically you
want it below the level at which you start binders, so for example,
for a cat in Stage 2 you want the phosphorus level below 4.6 mg/dl
or 1.5 mmol/L international. See
The
Importance of Phosphorus Control for more information on your
phosphorus goals.
The manufacturer recommends one pearl a day if you are feeding a
therapeutic kidney diet and two pearls a day if you are feeding another
commercial food or a homemade food.
Lanthanum Carbonate Dosage
Calculations and Adjustments
I expect your head is spinning now! I know quite a few people get confused
by all these recommended dosages, so here is a summary:
Recommendation
Cat Weight
Source
Total
Daily Dosage
per kg of
cat*
5 lb
2.27 kg
7.5 lbs
3.4 kg
10 lb
4.5 kg
12.5 lbs
5.7kg
IRIS
30-60 mg
68-136 mg
102-204 mg
135-270 mg
170-340 mg
Dr Chew
35-50 mg
80-114 mg
119-170mg
158-225 mg
200-285 mg
ISFM**
30-90 mg
68-204 mg
102-306 mg
135-405mg
170-513 mg
Renalzin
400 mg per cat per day
400 mg
400 mg
400 mg
400 mg
Total Range
30-90 mg
68-204 mg
102-306 mg
135-405mg
170-513 mg
*A kg is 2.2 lbs
**These are starting dosages, and can be increased if they are not
sufficient to reduce
your cat's blood phosphorus levels
Remember, the amounts given are the total daily dosage.
The total amount should be divided among as many of your cat's daily meals
as possible, ideally with larger meals receiving a larger proportion of
the daily dose (see Mixing with Food below).
See
below for how to
give binders, including how to mix them with your cat's food.
It is usually best to start at the lower recommended levels, increasing
the dose only if your cat's blood phosphorus levels do not reduce, but be
guided by your vet. See
The
Importance of Phosphorus Control for more on your
phosphorus goals.
Lanthanum Carbonate:
Choosing a Dosage
The
ranges for how much to give are quite wide, so talk to your vet
about a suitable starting point for your cat.
Taking
all the experts' recommendations above, here is what I would
probably try myself. However, this is just my opinion, and if your
vet recommends a different dosage regimen, you should of course
follow your vet's advice:
Cat's Phosphorus Level mg/dl
Cat's Phosphorus Level mmol/L
Possible Starting Daily Dose
Below 6
Below 1.9
30 mg per kg of cat
14 mg
per lb of cat
Between 6 and 7
Between 1.9 and 2.25
60 mg
per kg of cat
27 mg
per lb of cat
Above 7
Above 2.25
90 mg
per kg of cat
40 mg
per lb of cat
Lanthanum Carbonate: Adjusting a Dosage
Your
cat's blood phosphorus levels should start falling 7-10 days after
starting a phosphorus binder. Your vet should check your cat's blood
phosphorus levels 10-14 days after starting a binder. If your cat's
blood phosphorus level is not falling, you should discuss increasing the dose
you are using with your vet. If the phosphorus level seems to be
falling, I would continue with the dosage you are using.
I am
often asked if you should stop using a binder or adjust the dosage
once your cat's blood phosphorus has fallen to a satisfactory level.
Normally you will need to continue with the binder. In most cases,
you will need to continue with the dosage that reduces your cat's blood
phosphorus levels to your target level, but you can of course
speak to your vet about adjusting the dose, either upwards or
downwards, if necessary, e.g. if your cat's CKD starts to worsen and
phosphorus levels start to rise again.
Phosphorus binders must be given with food so they can bind with the
phosphorus in it. See below
for how to give binders.
Lanthanum Carbonate-based BindersSide Effects
The most common side effects for humans taking
lanthanum carbonate are nausea, vomiting and diarrhoea,
and I have also heard of CKD cats who developed nausea and vomiting whilst
taking Renalzin. The manufacturer confirmed to one person's vet that
these were possible side effects.
In 2011 the US Food
and Drug Administration issued a
Safety Labeling Change which states "There
have been reports of serious cases of
gastrointestinal obstruction, ileus, and fecal impaction reported in
association with lanthanum, some requiring surgery or
hospitalization. Risk factors for gastrointestinal obstruction
identified from post-marketing reports include alteration in
gastrointestinal anatomy (e.g., history of gastrointestinal surgery, colon
cancer) hypomotility disorders (e.g., constipation, ileus, diabetes) and
concomitant medications (e.g., calcium channel blockers). Some cases were
reported in patients with no history of gastrointestinal disease."
Amlodipine, used to treat high blood pressure in CKD cats, is a
calcium channel blocker, so check with your vet before using both.
"Due to
varying effects of intestinal phosphate binders to limit absorption of
drugs, it is advisable to give other drugs 1 hour before or 3 hours after
any intestinal phosphate binder is given."
Plumbs Veterinary Drugs Handbook says "Drug
interactions with lanthanum carbonate have not been reported, but as it is
a binding agent similar to aluminum, it seems prudent to separate by two
hours dosing lanthanum and the following:"
Baytril,
an antibiotic. Renalzin is not absorbed into the digestive tract like aluminium hydroxide-based binders, and therefore should have fewer possible interactions with
other treatments. Nevertheless, Bayer recommends that it
should be separated from any other medications by 1-3 hours, particularly
benazepril. Please see
below for
more on possible interactions.
It is probably wise to keep lanthanum
carbonate away
from
antibiotics
generally, particularly those in the same family as Baytril (this includes
Zeniquin).
I don't know if
slippery elm
bark would interfere with
lanthanum carbonate, as far as I know this
has never been studied, but it might be possible in theory. However, if
you are adding Slippery Elm Bark to food once or twice a day, I would
still mix binders in with that food in the hope that at least some of the
phosphorus would be bound.
Calcium-Based
Binders
Sometimes your vet will recommend using a calcium-based
antacid as a phosphorus binder. Over the counter products, such as Tums or PhosLo, are widely available and cheap but many vets also sell commercial products made for cats, all of which
have additional ingredients and cost a lot more. See
below for stockists.
The calcium acetates (e.g. PhosLo) bind 2-3 times as much phosphorus as
calcium carbonate (e.g. Tums). On the other hand, they are more likely to
cause elevated calcium levels in the blood (hypercalcaemia). They also do
not bind as much phosphorus as aluminium hydroxide or lanthanum carbonate
binders.
A kg is 2.2 lbs, so for a
10lb (4.5kg) cat, you would give 135-200mg of binder
three times a day or 202mg of binder twice a day, resulting in a daily total of 405mg of binder.
The
International Renal Interest Society (IRIS)
Treatment recommendations for CKD in cats
(2019)International Renal Interest Society
recommends using binders if phosphorus levels are as shown in the tables
despite dietary restriction of phosphorus:
USA
Stage of CKD
Creatinine Level mg/dl
Current
Phosphorus Level mg/dl
Binder Dosage
IRIS Stage 2
Between
1.6 and 2.8
Above 4.6
14-28 mg per lb of cat per day
IRIS Stage 3
Between 2.9
and 5.0
Above 5.0
14-28 mg per lb of cat per day
IRIS Stage 4
Over 5.0
Above 6.0
14-28 mg per lb of cat per day
International
Stage of CKD
Creatinine Level mmol/L
Current Phosphorus Level mmol/L
Binder Dosage
IRIS Stage 2
Between
140 and 249
Above 1.5
30-60 mg per kg of cat per day
IRIS Stage 3
Between 250
and 439
Above 1.6
30-60 mg per kg of cat per day
IRIS Stage 4
Over 440
Above 1.9
30-60
mg per kg of cat per day
As you
can see, the recommended amounts of binder are actually the same for
each stage. What is different is:
firstly,
when you start treating for high phosphorus levels. For example, for
a cat in IRIS Stage 2 you would start treating a phosphorus level
above 4.6 mg/dl or 1.5 mmol/L international, whereas for a cat in
Stage 3 a level above 4.6 mg/dl (1.6 mmol/L international) would be
acceptable as long as it was no higher than 5 mg/dl (1.9 mmol/L
international).
secondly,
the target phosphorus level for each stage of CKD. Basically you
want it below the level at which you start binders, so for example,
for a cat in Stage 2 you want the phosphorus level below 4.6 mg/dl
or 1.5 mmol/L international. See
The
Importance of Phosphorus Control for more information on your
phosphorus goals.
Calcium Carbonate
You can buy calcium carbonate-based binders over the
counter — Tums is a widely available product of this type.
The risk of hypercalcaemia is lower with calcium
carbonate-based binders than with calcium
acetate-based, though it still exists. Calcium carbonate-based products only bind a third to
a half of
the phosphorus that calcium acetate-based binders bind, and a lot less
than aluminium hydroxide or lanthanum carbonate.
A
number of manufacturers now make calcium carbonate-based products for
cats, most of which have additional ingredients, as follows:
These are the
recommended dosages for over the counter calcium carbonate products. If
you are using one of the branded products discussed below, follow the
manufacturer's recommendations after discussion with your vet.
A kg is 2.2 lbs, so for a
10lb (4.5kg) cat, you would give 135-200mg of binder
three times a day or 202mg of binder twice a day, resulting in a daily total of 405mg of binder.
The
International Renal Interest Society (IRIS)
Treatment recommendations for CKD in cats
(2019)International Renal Interest Society
recommends using binders if phosphorus levels are as shown in the tables
despite dietary restriction of phosphorus:
USA
Stage of CKD
Creatinine Level mg/dl
Current
Phosphorus Level mg/dl
Binder Dosage
IRIS Stage 2
Between
1.6 and 2.8
Above 4.6
14-28 mg per lb of cat per day
IRIS Stage 3
Between 2.9
and 5.0
Above 5.0
14-28 mg per lb of cat per day
IRIS Stage 4
Over 5.0
Above 6.0
14-28 mg per lb of cat per day
International
Stage of CKD
Creatinine Level mmol/L
Current
Phosphorus Level (mmol/L)
Binder Dosage
IRIS Stage 2
Between
140 and 249
Above 1.5
30-60 mg per kg of cat per day
IRIS Stage 3
Between 250
and 439
Above 1.6
30-60 mg per kg of cat per day
IRIS Stage 4
Over 440
Above 1.9
30-60
mg per kg of cat per day
As you
can see, the recommended amounts of binder are actually the same for
each stage. What is different is:
firstly,
when you start treating for high phosphorus levels. For example, for
a cat in IRIS Stage 2 you would start treating a phosphorus level
above 4.6 mg/dl or 1.5 mmol/L international, whereas for a cat in
Stage 3 a level above 4.6 mg/dl (1.6 mmol/L international) would be
acceptable as long as it was no higher than 5 mg/dl (1.9 mmol/L
international).
secondly,
the target phosphorus level for each stage of CKD. Basically you
want it below the level at which you start binders, so for example,
for a cat in Stage 2 you want the phosphorus level below 4.6 mg/dl
or 1.5 mmol/L international. See
The
Importance of Phosphorus Control for more information on your
phosphorus goals.
Ipakitine/Epakitin
(Calcium Carbonate and Chitosan)
Ipakitine
has been available in the UK since December 2002 and in the rest of Europe
for even longer. Ipakitine was introduced into the USA in 2005, under the
slightly different name of
Epakitin.
I have not been able to find out exactly how much
calcium carbonate is in Ipakitine in the UK or Epakitin in the USA,
however:
Drugs states that 1g of the Canadian
version of Epakitin contains 100mg of calcium carbonate and 80mg of
chitosan.
Chronic kidney disease (CKD) in dogs and cats - staging and management
strategies (2015) Chew D A Presentation
to the Virginia Veterinary Medical Association 2015 Virginia Veterinary
Conference states that it contains 8% chitosan and 10% calcium
carbonate, which would tie in with this.
I presume the US and European versions are the same.
The recommended dose is 1g of Epakitin per 5kg (11 lb)
of cat given twice a day with meals.
This equates to 200mg of calcium carbonate per day for
an 11 lb (5kg) cat.
This is within typical veterinary guidelines for
calcium carbonate dosages, see
above.
Effects of an intestinal phosphorus binder on serum
phosphorus and parathyroid hormone concentration in cats with reduced
renal function (2008) Brown SA,
Rickertson M & Sheldon S International Journal of Applied Research in
Veterinary Medicine6(3) pp155-160 reports on a small
randomised placebo-controlled study of twelve cats at the University of
Georgia College of Veterinary Medicine (partly funded by the
manufacturers) which indicated that Epakitin reduced phosphorus levels in
the cats, who were fed a commercial non-therapeutic diet and who were
in
IRIS Stages 1 and 2. The study did not find that Ipakitine
reduced BUN or creatinine levels, however the cats in this
study did not have naturally occurring kidney disease, which the cats in
the 2004 study below did.
In the USA, Epakitin is marketed as both a "nutraceutical"
and a "nutritional supplement." In the marketing literature, emphasis
seems to be placed on its role as a phosphorus binder, but many vets seem
to sell it to clients whose cats do not have elevated phosphorus levels,
so they are presumably advocating it for its chitosan-related effects.
Perhaps because
it is not considered to be purely a phosphorus binder, the recommendation
is to give it twice a day rather than divided between all meals. Although
ideally you should divide the total daily dose between all meals, it does
seem to work to a degree when given twice a day. My own vet in the UK has seen
falls in creatinine and urea in some cats when using Ipakitine and no
other treatments. I used it myself for Ollie who did
not have very high phosphorus levels, and to whom none of the
cautions below applied.
It did appear to reduce his phosphorus levels.
Ipakitine is only supposed to be given for six months, but I
have heard of cats who have been on it for longer with no obvious
problems. The manufacturer has stated it should be OK to give it for
longer for six months under veterinary supervision.
Ipakitine How To
Give
Ipakitine comes
in powder form, and is apparently tasteless. It is sprinkled on the cat’s
food for a period of up to six months, although it may be used for longer
if your vet agrees.
Dosage is
weight-related, and phosphorus levels do not appear to be taken into
account when determining how much to give.
Ipakitine Side Effects
and Interactions
The
Material Safety Data
Sheet states that Ipakitine contains a high
(70-90) percentage of lactose,
so I would not use it if your cat is lactose intolerant.
Calcium-containing products such as Ipakitine may cause increased calcium
levels (hypercalcaemia).
The risk is lower with calcium carbonate-based binders
(such as Ipakitine) than with other calcium-based binders,
and the manufacturer claims it is less likely to happen with the form of calcium
carbonate which they use, but if your cat is taking Ipakitine, it would probably be wise to monitor
his/her calcium levels.
Ipakitine is
not normally suitable for cats who already have high calcium levels. It
also should not be used in cats taking
calcitriol.
Renal P by
Candioli (Calcium Carbonate and Chitosan)
Renal P is made by Candioli Pharma in Italy
and is commonly offered to people in Italy, and occasionally to people in
other parts of Europe.
Since not every CKD cat needs treatment for metabolic
acidosis, I would give Renal P a miss.
Aventi
Kidney Protect or RenalPro
Aventi Kidney Protect was previously the same product as
Renal P. It is commonly offered to people
in Canada, where it is marketed by Aventix Animal
Health.
Vet Rx Direct
has some information about it, and it now appears to be somewhat
different, in that it still has the calcium carbonate and chitosan, but
also has potassium citrate.
Drugs also
has some information about it.
RenalPro is
a similar product made by a Canadian company called ProConcepts Animal
Health. It also contains calcium carbonate, chitosan and potassium
citrate.
Personally, if my cat needed a potassium supplement, I would give it
separately, and if my cat didn't need a potassium supplement, why would I
give a product containing potassium?
Renaltan (Calcium
Carbonate and Chitosan, B Vitamins, Essential Fatty Acids and Minerals)
Renaltan is a liquid calcium carbonate-based phosphorus binder made by Recoactiv (RecoVet) in
Germany. It also contains some B
vitamins, essential fatty acids and minerals. 10ml contain 500mg of
calcium carbonate but the manufacturer's website
does not specify the precise amounts of any of the other ingredients.
The
manufacturer claims that this product stimulates the appetite and
increases food intake, which I presume is because of the B vitamins. It also claims that by using this product, you can
avoid using therapeutic kidney food in IRIS Stages 1 and 2 because you are controlling
phosphorus levels but leaving protein levels untouched. Whilst it is
true that it is not necessarily a good idea to reduce protein levels in
IRIS Stages 1 and 2 (see
Nutritional Requirements), therapeutic kidney diets do have other
attributes (see
Which Foods to Feed for information on when and why to use
therapeutic kidney diets).
I have heard from a few German users who seem to like Renaltan. It is
available from the manufacturer's own website (first link above), from
Tiernaturprodukte or from
Amazon Germany.
Easypill Kidney
Support Cat (Calcium Carbonate, Yucca and Essential Fatty Acids)
Easypill Kidney Support Cat is a
calcium carbonate-based phosphorus binder made by Vetinnov in France and
available in a number of European countries. As the name suggests, this
product is intended to offer high palatability.
As seems to be the custom with brand name calcium carbonate-based binders,
it contains additional ingredients:
Rather strangely, Easypill Kidney Support Cat contains 1.19% phosphorus on
a dry matter analysis basis.
I was told this is because chicken hydrolysate, which is used to make the
product palatable to cats, contains phosphorus.
The recommended dose is one 2mg pellet per day for three months.
I have not heard from anybody who has used this product as yet.
Pronefra (Calcium
and Magnesium Carbonate, Chitosan, Astralagus and Fish Protein Hydrolysate)
Pronefra,
made by Virbac, was launched in 2014. It is
marketed as a "supplementary food" and contains four main
ingredients:
calcium carbonate (3.57%) and magnesium
carbonate (0.95%) as phosphorus binders
fish protein hydrolysate (1.9%), which they claim
helps with hypertension.
Binders containing magnesium are not ideal for
CKD cats because they
can cause
high
magnesium levels in the blood, which in turn can sometimes cause
urinary tract problems such as stones in some cats.
PetCoach
states "Do not use magnesium containing products in
animals with kidney failure."
Astragalus is thought to be an antioxidant but
Holisticat
states that
astragalus should only be used short term in cats, see
Holistic Treatments.
Fish protein hydrolysate is also found in
Astro's Protein Powder,
though I am not sure whether Pronefra contains enough to make a
difference, and I have no idea how exactly it is supposed to help with
hypertension.
The recommended dose of Pronefra is 1 ml per 4 kg (9lbs) of cat twice a day,
mixed with food
or syringed directly into the cat's mouth immediately before or after
eating. I do not yet know how much calcium carbonate this would contain.
Comparative palatability of five supplements
designed for cats suffering from chronic renal disease(2014)
Bernachon N, Fournel S, Gatto H, Monginoux P & McGahie D Irish
Veterinary Journal67(1) p10 compared
the palatability of five products intended for CKD cats: Ipakitine,
Azodyl, Renalzin, Rubenal and Pronefra. The study, undertaken by employees
of Virbac, the manufacturer of Pronefra, found that Pronefra was the most
palatable.
I haven't heard from too many people who have used it as yet (February 2018),
but one person said it made her cat vomit and a couple of people said
their cats didn't like the taste. Personally, I don't think I would bother
with Pronefra.
Renate (Calcium and
Magnesium Carbonate, Curcumin, Cranberry, Vitamins)
Renate is yet another calcium
carbonate-based product (with lots of other ingredients to differentiate it
from its competitors) which was launched in the UK in 2017. It is not to be
confused with a product of the same name in the USA which is a
multivitamin designed for pregnant women.
Renate is intended to "aid renal function in cats." It contains:
It comes in a 2mg sachet and the dosage is one sachet a day, divided
between all that day's meals. I am trying to find out how much calcium
carbonate that contains.
Binders containing magnesium are not ideal for
CKD cats because they
can cause
high
magnesium levels in the blood, which in turn can sometimes cause
urinary tract problems such as stones in some cats.
PetCoach
states "Do not use magnesium containing products in
animals with kidney failure."
I do not recommend
cranberry for CKD cats, nor would I want to give
curcumin.
Calcium-based Binders
Side Effects
Hypercalcemia in cats (2001) Chew D Presentation to the World Small Animal Veterinary Association
World Congress 2001
mentions that using calcium-based
binders may cause
hypercalcaemia. Thus, if you are using a
calcium-based binder, frequent monitoring of blood calcium levels
is essential.
Chronic kidney disease (CKD) in dogs and cats — staging and management
strategies (2015) Chew D A Presentation to the
Virginia Veterinary Medical Association 2015 Virginia Veterinary
Conference states that "Calcium
carbonate binds phosphorous best in an acidic environment (pH approx. 5)
and binding capacity is reduced in the neutral pH range. Many CKD patients
receive inhibitors of gastric acid secretion potentially reducing calcium
carbonates ability to bind phosphorous." I did use calcium-based
binders and famotidine with Ollie with no problems, but if you are using products
such as
famotidine (Pepcid AC) or
omeprazole (Prilosec), I would discuss the situation with your vet.
There are two types of sevelamer-based binders, sevelamer hydrochloride
and sevelamer carbonate.
Sevelamer-based binders are very expensive, but may be worth considering
if you cannot use the other types of binders for some reason, though there
is little evidence for their use in cats.
Chronic kidney disease (CKD) in dogs and cats - staging and management
strategies (2015) Chew D Presentation to the
Virginia Veterinary Medical Association 2015 Virginia Veterinary
Conference
says "Many human clinical studies have demonstrated the
ability of sevelamer hydrochloride to lower serum phosphorous, and
parathyroid hormone levels, and control Ca x P product in dialysis
patients compared with calcium containing phosphate binders. Their
effects on dogs and cats with clinical CRF, however, have not been
reported."
Renagel (sevelamer hydrochloride) is a relatively new
phosphorus binder approved for use in humans, with not much history
of use in cats.
CenterWatch has information on the
approval of Renagel for use in the USA.
Renal disease in cats
(2013) Gunn-Moore DA Crieff 2 Day Small Animal CPD Meeting pp125-144 says "Some clinicians have
also used sevelamer hydrochloride, but anecdotally this appears less
effective than lanthanum."
Renvela:Sevelamer Carbonate
Renvela
(sevelamer carbonate) is the next generation version of Renagel which
contains a carbonate buffer. It is intended to help with bicarbonate levels.
A kg is 2.2 lbs, so for a
10lb (4.5kg) cat, you would give 150-240mg of binder
three times a day or 225-360mg of binder twice a day, resulting in a daily total of
450-720mg of binder.
Sevelamer-based BindersSide Effects and Interactions
Sevelamer
may cause constipation.
Another more worrying problem is interference with blood clotting, so if
you use it, it may also be necessary to give your cat vitamin K.
Iron-Based Binders:
Lenziaren and Velphoro
Lenziaren
Lenziaren (also known as SBR759) is a new phosphorus binder for cats
derived from iron oxide. It has been available in
Japan and Taiwan since 2013 and presumably Novartis, the
manufacturer, will be releasing it in other markets in due course.
Efficacy, acceptability and tolerability of the new
oral phosphate binder Lenziaren in healthy cats fed a standard diet
(2014) King JN, Erasmus HL, Delport PC, Bester ICJ & Seewald W BMC
Veterinary Research10(258) found that Lenziaren seemed to be
well tolerated when added to food. Iron levels also increased, as you
might expect from an iron-based binder, but so did food intake. This trial
was conducted in healthy cats, and found that when these healthy cats were
given higher doses of Lenziaren, their phosphorus levels actually
increased. The manufacturer is currently investigating this.
Like me, you may be wondering why Lenziaren was fed to healthy cats. This
is probably because, according to
Scientific opinion on the safety and efficacy of
Lenziaren (iron, aqua carbonate hydroxyl oxo starch sucrose complex) as a
feed additive for cats (2013) Panel on Additives and Products
or Substances used in Animal Feed European Food Safety Authority
Journal 11(5) p3204-5, Lenziaren is "intended to be used in
food for adult cats to reduce phosphate absorption in the gastrointestinal
tract in order to prevent chronic kidney disease." Whilst phosphorus
restriction may possibly be appropriate for older cats who may develop CKD
in the near future (see
Prevention),
I would have thought feeding a somewhat lower phosphorus food would be a
better first step. The panel concludes "Lenziaren has the potential to be
efficacious in cats at the highest recommended dose of 1 g/cat per day
(equivalent to 20 000 mg/kg feed). However, the FEEDAP Panel has some
reservations regarding the value of its long-term use in healthy cats. The
Panel concludes that there is a need for a post-market monitoring plan."
In a revised version of the scientific opionion, found
here, the panel "considers that Lenziaren
has the potential to be efficacious in binding intestinal phosphorus at
the minimum recommended dose of 0.25 g/cat per day."
Efficacy and acceptability of the new oral phosphate
binder Lenziaren in healthy cats fed a renal diet
(2015) King JN, Delport PC, Luus HG, Erasmus HL, Barnes PM
& Speranza C Journal of Veterinary Pharmacology and Therapeutics38(3)
pp278–289 refers to earlier field trials which indicated that an effective
dose for CKD cats was 0.5-2.0g per day, added to meals, and that, unlike
the healthy cats in the above study whose phosphorus levels rose on higher
doses, their phosphorus levels reduced at this dosage.
I have heard from a couple of people in those countries where Lenziaren is
available who have used it in their CKD cats and found it effective. I
think if I were to use it, I would monitor my cat's iron levels as well as
phosphorus.
Velphoro
Velphoro
(sucroferric oxyhydroxide), previously known as PA21, is a new binder
which was launched in the USA in 2014 for humans on dialysis. It is
also iron-based and comes in a chewable form. Apparently it binds phosphorus
more effectively than sevelamer in human dialysis patients. The most
common side effect is diarrhoea. I do not know anyone who has used it in cats as yet but will report
further should that happen.
the
minimum recommended dose of Lenziaren is 0.25g/cat per day
the highest recommended dose is 1 g/cat per day.
Niacinamide (Vitamin B3)
In late 2017 I began to receive messages asking why I don't mention using
niacinamide (vitamin B3) as a phosphorus binder. I did actually refer to
this use of niacinamide on the
vitamin B page, but since people do not
seem to have noticed it there, I am now including the information here,
in expanded form.
Niacin is vitamin B3. In the body it may be converted into the active
form, which is known as
niacinamide or nicotinamide.
Vitamin B3 is important for processing lipids, amino acids and glucose
within the body. A deficiency can affect appetite and red blood cell
production. Vitamin B3 is an essential vitamin for cats, i.e. they cannot
produce it within their bodies, so they must ingest it.
Niacinamide used as a binder has a somewhat different mechanism to other
binders.
Use of nicotinamide to treat hyperphosphatemia in
dialysis patients (2013) Lenglet A, Liabeuf S, Guffroy P,
Fournier A, Brazier M & Massy ZA Drugs in R&D13(3)
pp165-173 says "In vitro and in vivo data show that nicotinamide reduces
hyperphosphatemia by inhibiting sodium-dependent phosphate co-transport in
the renal proximal tubule and in the intestine. Accordingly, targeting the
sodium-dependent phosphate co-transporter 2b by using nicotinamide as an
alternative or adjunct to classical phosphate binders may be a therapeutic
option for modulating serum phosphate in CKD." Since it does not bind
with phosphorus in food, it is not necessary to give it with every meal.
Niacinamide Formulations
Vitamin B3 is widely available as either niacin (nicotinic acid) or as niacinamide
(nicotinamide), either by
itself or as part of a
vitamin B complex
product.
It is usually better to use niacinamide, particularly when giving
higher doses. This is because giving niacin may lead to a
niacin flush, which can cause tingling, itching and redness (unlikely to be
visible in a cat) and headaches. Occasionally breathlessness may be seen. These symptoms
usually only last an hour or so, but can be unpleasant. A niacin flush is more common with
higher doses or when the vitamin is taken on an empty stomach. It may
still happen when using niacinamide at higher doses, but is much less likely.
Niacin flushes usually stop as the body gets used to the medication.
Niacinamide Research
There has been some research in humans into the use of niacinamide to
control
phosphorus levels in CKD patients, usually patients receiving dialysis
(which very few cats are given).
I am not aware of any research into the use of vitamin B3 in cats. The
following studies relate to humans.
Another trial in human patients on
dialysis,
The effect of niacin on serum phosphorus levels in
dialysis patients (2012) Edalat-Nejad M, Zameni F & Talaiei A
Indian Journal of Nephrology22(3) pp174–178, also looked at
using niacin in addition to other binders. It states "The main troublesome
constraint in our study was the erratic changes in phosphorus values
caused by food variety. Although, we had a dietician on hand to counsel
patients almost throughout the study period, the influence of food variety
effect is irrefutable especially because of the short duration of the
study. Conclusions Our study suggests niacin may emerge as a safe,
low-cost therapy in combination with other phosphate binders for phosphate
control. The modest increase in HDL values may be another beneficial
effect of this treatment. However, larger and longer term controlled
trials are needed to establish the optimal dosage and the clinical
significance of niacin treatment."
There was a fall in platelet counts in both these studies, though not a
major one.
In
Safety and efficacy of nicotinamide in the
management of hyperphosphatemia in patients in hemodialysis
(2011) Vasantha J, Soundararajan P, Vanitharani N, Kannan G,
Thennarasu P, Neenu G & Umamaheswara Reddy C Indian Journal of Nephrology21(4) pp245–249, human patients receiving dialysis were given 250mg
of nicotinamide twice daily if their phosphorus level was over 5 mg/dl,
and three times daily if their phosphorus level was over 8 mg/dl, in both
cases for eight weeks. The study states "A statistically significant
decrease of mean serum phosphorus was found at the 4th and at the end of
8th week of nicotinamide therapy," and also says "There was a slight decrease in mean creatinine and BUN levels, which
was not statistically significant."
Effects of low-dose niacin on dyslipdemia and serum
phosphorus in patients with chronic kidney disease
(2013) Kang HJ, Kim DK, Lee SM, Kim KH, Han SH, Kim
KH, Kim SE, Son YK & An WS
Kidney Research and Clinical Practice32(1)
pp21-26 looked at human patients who took 500mg of
niacin daily for six months. It states "In the niacin group, phosphorous
level (P<0.05) was significantly decreased, and glomerular filtration rate
(GFR) was significantly increased (P<0.05) at 24 weeks compared with
baseline values."
Effect of low dose nicotinic acid on
hyperphosphatemia in patients with end stage renal disease
(2016) Zahed NS, Zamanifar N & Nikbakht H Indian Journal of
Nephrology26(4) pp239–243 used lower doses and still found
them effective. They gave human patients 25mg/day of niacin for 12 weeks;
if patients failed to respond (phosphorus did not fall below 5.5 mg/dl),
the dose was increased up to 50 mg/day after four weeks and 100mg/day
after eight weeks. The study found that "Niacin 100 mg/daily decreased
phosphorus serum levels and increased HDL serum levels in patients with
ESRD that undergo dialysis."
Fibroblast growth factor 23 (FGF-23) is important for the regulation of
phosphorus levels in the body. FGF-23 levels may in fact rise before other signs of CKD appear. In
humans, such increases have been identified before any changes in PTH and
phosphorus levels.
Effect of niacin on FGF23 concentration in chronic
kidney disease (2014) Rao M,
Steffes M, Bostom A & Ix JH American Journal of Nephrology39(6)
pp484-490 found that in human patients "extended release niacin alone, but not in
combination with laropiprant, lowered FGF23 and PTH concentrations. If
confirmed, niacin may provide a novel strategy to decrease phosphorus,
FGF23, and PTH concentrations in patients with CKD."
Use of nicotinamide to treat hyperphosphatemia in
dialysis patients (2013) Lenglet A, Liabeuf S, Guffroy P,
Fournier A, Brazier M & Massy ZA Drugs in R&D13(3)
pp165-173 says "Several recent clinical
studies have explored the potential value of nicotinamide in phosphate
control (as well as its effects on lipid levels) in dialysis patients.
However, we consider that more data on pharmacodynamics, pharmacokinetics
and safety are needed before this compound can be recommended as a
treatment for hyperphosphatemia in ESRD patients."
In early 2013 several members of my support group began using it in their cats after consultation with their vets. None of them
continued to use it in this way as far as I know, but unfortunately none
of them reported back on their experiences so I do not know for sure, and
if they did stop using it, I don't know why. Another member started using
niacinamide at a later date and used it for over a year, finding it very
effective as a binder and with no real side effects.
Niacinamide Dosage
For general intake to maintain health in cats,
Your cat's nutritional needs (2006)
National Research Council
recommends that a
9 lb (4 kg) healthy cat eating 250 calories per day should receive
a total intake of 2.5mg of vitamin B3 a day.
Nutritional management of renal disease
(2008) Sturgess K Presentation to the World Small Animal
Veterinary Association World Congress suggests that a CKD cat should
receive 3.6-7.2mg a day. This
is total intake, i.e. it includes vitamin B in food.
The maximum safe dose for cats has never been assessed.
In the above studies into the use of niacin to control phosphorus levels in humans, widely varying
doses were used, so it can be difficult to know the optimum dose for a
human, let alone a cat.
Members of Tanya's CKD Support Group who used niacinamide to control
phosphorus levels in
2013 began with 50mg of niacinamide.
Some of them then gradually increased the dosage to 80-100mg daily. It is
best to start low and increase gradually in order to avoid possible side
effects, such as loss of appetite or diarrhoea.
I have also heard from people who are giving 250mg once or twice a day.
This is based on a suggestion from Dr Mandelker, a vet posting on
the Veterinary Information Network. He has kindly confirmed to me that he
has used this dosing schedule, and believes niacinamide is a safe binder, but
he did mention it is not as effective as aluminium hydroxide.
I would not give vitamin B3 to your cat without discussing a suitable dose
with your vet first. Since
vitamin B3 may cause a
niacin flush,
it is important to start low and increase the dose slowly.
Niacinamide often tastes bitter, so it is probably best to give it in a
gelatine
capsule.
Amazon sells 100 Jarrow niacinamide 250mg
capsules for around US$5.
Niacinamide is thought to be less likely to cause side effects than niacin, but
they may still occur. See
above for
information on the niacin flush.
Other possible side effects include upset stomach, reduced appetite and dizziness.
In humans, more serious side effects have been seen with doses of over 3g
of niacin per day, including increased liver enzymes, high blood sugar
levels, stomach ulcers, irregular heart beat and even blindness.
Diabetes is also a possible concern with long term use, because blood sugar levels
may increase, requiring an adjustment of insulin if your cat is on this.
Dr Larry Nagode, formerly of Ohio State University College of Veterinary
Medicine, has stated that niacin and niacinamide may increase calcium
levels.
Safety and efficacy of nicotinamide in the
management of hyperphosphatemia in patients in hemodialysis
(2011) Vasantha J, Soundararajan P, Vanitharani N, Kannan G,
Thennarasu P, Neenu G & Umamaheswara Reddy C Indian Journal of Nephrology21(4) pp245–249 states in respect of the human patients in the study "Regarding the adverse drug reactions of nicotinamide, watery stools
were reported in seven patients and it resolved on continuation of
therapy not requiring any dosage adjustment or therapy with other
drugs. Thrombocytopenia that is commonly associated with niacinamide
and nicotinic acid therapy was not reported by any of the patients.
Other than alkaline phosphatase levels all the liver function tests
were normal. Blood sugar levels were also not affected by nicotinamide
therapy."
There has been some debate about the possibility of niacin increasing the
risk of stroke in people.
Extended-release niacin therapy and risk of ischemic
stroke in patients with cardiovascular disease
(2013) Teo KK, Goldstein LB, Chaitman BR, Grant S, Weintraub WS,
Anderson DC, Sila CA, Cruz-Flores S, Padley RJ, Kostuk WJ, Boden WE and on
behalf of the AIM-HIGH Investigators Stroke44 pp2688-2693
looked at the use of niacin in addition to other heart medicine in humans
with known heart disease. Initial results in this trial indicated an
increased risk of stroke in patients taking extended release niacin, but
the final report states "Although there was a numeric excess in ischemic
strokes associated with the addition of niacin to simvastatin, the number
of events was small, and multivariate analysis accounting for known risk
factors did not support a significant association between niacin and
ischemic stroke risk."
Web MD has some information on possible
side effects.
Drugs has some information about niacin
side effects.
Drugs also has some information about
niacinamide side effects.
Which Binder to Choose
It can be difficult deciding which binder to use. Traditionally people
used aluminium hydroxide, but this is now harder to find in the USA, and
some people are uncomfortable about the possibility of aluminium toxicity.
Many members of Tanya's CKD Support Group
switched to lanthanum carbonate for these reasons, but following the
discontinuation of Renalzin, it is not easy to find this cheaply.
Here is a summary of the pros and cons of each binder type, followed by my
own experiences and thoughts. Ultimately, if your cat needs a phosphorus
binder, I would say the most important thing is that s/he receives one.
Aluminium Hydroxide
Binders:
Pros and Cons
Pros
They
are very effective, are available over the counter (at
least in theory), are cheap, and have no taste or smell so most cats are
prepared to eat them in their food.
Cons
They may cause constipation, may need to be tracked
down in the USA, and there is a risk, albeit a relatively small one, of
aluminium toxicity.
Lanthanum Carbonate Binders: Pros and
Cons
Pros
They are very effective (as effective as
aluminium hydroxide) and have little taste or smell so most cats are prepared
to eat them in their food.
Cons
Renalzin has been discontinued and alternative products
are very expensive. Lanthanum-based products may cause constipation, and serious problems
may be seen if given to
patients who are constipated, diabetic or using a calcium channel blocker
(such as
amlodipine for high blood pressure).
Calcium-based Binders:
Pros and Cons
Pros
They are cheap, available over the counter and there
are a variety of commercial preparations which are formulated to be
palatable and to provide possible additional benefits (though these are
not as cheap).
Cons
They do not bind phosphorus as effectively as aluminium
hydroxide or lanthanum, and may cause elevated calcium levels. Some may
also interact with stomach acid blockers such as famotidine (Pepcid AC).
Sevelamer-based Binders:
Pros and Cons
Pros
They may be helpful for cats who cannot use the other
types of binder for some reason.
Cons
There is
little history of use in cats but these binders appear to be less
effective than lanthanum. They may cause problems with blood clotting,
and
may cause elevated calcium levels. Like
many other binders, they can cause constipation.
Iron
-based Binders:
Pros and Cons
Pros
Appear to be effective, based on limited studies and
feedback I have received. One study found this type of binder seemed to improve appetite,
though that study used healthy cats.
Cons
Not yet
available in western countries. May be necessary to monitor iron levels as
well as phosphorus levels. Phosphorus levels actually increased in the
healthy cats who received this type of binder.
Niacinamide-based
Binders: Pros and Cons
Pros
They are available over the counter, are cheap and widely available.
Cons
There are few reports of use in cats, and there is no research available for cats.
My Experiences
I have used aluminium hydroxide and Ipakitine (which is
calcium carbonate-based) for my cats. I have not used lanthanum, sevelamer, iron-based
binders or niacinamide (vitamin B3).
Both aluminium hydroxide and Ipakitine worked just fine
for my cats. As far as the Ipakitine went, Ollie did not have particularly
high phosphorus levels to start with, whereas Thomas, who received
aluminium hydroxide, did.
My own vet in the UK has seen falls in creatinine and
BUN (urea) in some cats when using
Ipakitine and no other treatments.
In principle I would certainly be happy to try lanthanum carbonate,
but since it is now horrendously expensive following the withdrawal of
Renalzin from the market, I doubt I would bother.
Personally, I would probably reach first for aluminium hydroxide,
not least because it is effective, relatively easy to obtain in the UK and not too expensive.
However, if I had a cat in early stage CKD with moderately elevated blood
phosphorus levels (between 6 and 7 mg/dl (USA) or 1.9 and 2.25
mmol/L (international)
but normal blood calcium levels, I would consider using
a commercial calcium carbonate preparation such as Ipakitine because my vet is
very familiar with it, it is easy to source, not too
expensive, and it may have additional benefits. I would ask my vet to
monitor my cat's blood calcium levels.
For a cat with higher phosphorus levels (over 7 mg/dl (USA) or 2.25 mmol/L
(international),
or a cat with moderately elevated phosphorus levels but elevated calcium
levels, I would definitely opt to use an aluminium hydroxide binder. Even for cats
with lower phosphorus levels, if the cat's phosphorus multiplied by
total calcium is higher than 70in US
values or 5 in international values, the cat is at risk of tissue
calcification (see
secondary
hyperparathyroidism). In such a case, again I would opt to
use an aluminium hydroxide binder in order to get the
phosphorus levels under control as quickly as possible.
Don't forget, if the binder you choose doesn't seem to
be helping, or doesn't seem to suit your cat, you can always try another,
either instead of or in addition to the binder you are using.
The most important thing, if your cat needs a binder,
is to use one.
Combining Binders
If you are
having trouble getting phosphorus under control using one type of binder
alone, you can use another in addition to the first. This often is the
case when people do not wish to give higher doses of aluminium
hydroxide-based binders, so choose to add lanthanum carbonate.
In
such cases, you would give the lower doses of aluminium hydroxide outlined
above and then add lanthanum carbonate. A suitable starting dose of
lanthanum carbonate might be 50-100mg per kg of cat per
day, which equates to a bit less than 25-50 mg per lb of cat per day. You can go up to
200mg per kg of cat
per day (just under 100mg per lb of cat per day) if necessary, but
obviously work with your vet on determining the most appropriate dosage
for your cat.
It is fine in this situation to mix the binders when
you give them. So if, for example, you feed your cat three times a day,
you can calculate how much aluminium hydroxide you need to give in total
for the day and how much lanthanum carbonate you need to give in total for
the day, and then give a third of each to your cat with each meal.
Phosphorus binders (apart from niacinamide) must be given with food so they can
bind with the phosphorus in it.
Chronic kidney disease (CKD) in dogs and cats - staging and management
strategies
(2015) Chew D A Presentation to the
Virginia Veterinary Medical Association 2015 Virginia Veterinary
Conference says "Intestinal phosphate binders work best when
given with meals or within 2 hours of feeding to maximize their binding of
dietary phosphorus."
Personally I think within two hours of feeding is
pushing it. One human study,
Effectiveness of aluminum hydroxide timing
administration in relation to meals in controlling hyperphosphatemia in
dialysis patients (2005) Katopodis
KP, Andrikos E, Pappas M & Siamopoulos KC The International Journal of
Artificial Organs28(8) pp803-7, found that giving aluminium
hydroxide binders 30 minutes before eating only reduced phosphorus levels
by 7%, whereas administering them mixed with food or up to 30 minutes
after the meal reduced phosphorus levels by 28.5%.
The test is to give the binders the way that works best
for you and check your cat's blood phosphorus levels after about two
weeks, when with luck they will be falling nicely.
People used to be confused that the dosage of phosphorus binder
recommended did not take into account the size of the meal being consumed.
Specialists such as Dr Chew in
Chronic kidney disease (CKD) in dogs and cats - staging and management
strategies
(2015) A Presentation to the
Virginia Veterinary Medical Association 2015 Virginia Veterinary
Conferenceare now advising that "The
dose of any phosphate binder should be based on the meal size (phosphorus
intake) and the prevailing serum phosphorus level for each CKD patient;
the dose is titrated to effect." Obviously this is the ideal, so if you
know, for example, that your cat always eats larger meals in the evening
than in the morning, you can adjust the dose accordingly.
How to Mix
Binders with Food
Aluminium hydroxide and many other
binders are
usually odourless and tasteless if you choose carefully, though they can sometimes add a bit of a gritty
texture to food or make it taste a little drier.
Most people find it easiest to add the binders
to the cat's food, though if the manufacturer of your binder makes a
different recommendation, be guided by that.
Giv
ing Binders with Canned
Food
tablets can simply be crushed
and added to the food.
capsules can be opened and the contents mixed with the food (after
measuring as above).
liquid binders can either be mixed in the food or
syringed into your cat's mouth just before eating.
one retailer recommends adding a teaspoon of
water to the tinned food and binder and letting it stand for ten minutes before serving
in order to let the binder mix thoroughly. This may
help remove any grittiness.
Giv
ing Binders with Dry Food
try putting the food in a freezer bag together with the crushed
or powder binder and leave them to mingle
overnight.
if you are using a liquid binder, you can syringe it
into your cat's mouth just before eating.
How Long For Binders to Work
You should see an improvement in your cat's blood
phosphorus levels after 7-10 days. You may see a
difference in your cat's demeanour sooner than this. Check your cat's phosphorus level every
two weeks until the level is acceptable, then check it every 2-3 months to see if any
adjustments to your treatment plan are necessary.
In theory, a cat receiving binders may
develop the opposite of what you are trying to treat, i.e. low phosphorus
levels (hypophosphataemia).
Chronic kidney disease (CKD) in dogs and cats - staging and management
strategies (2015) Chew D A Presentation to the
Virginia Veterinary Medical Association 2015 Virginia Veterinary
Conference, Dr
D Chew states "it is difficult for
this to develop in those with initially high concentrations of serum
phosphorus." However, in
Renal disease in cats
(2013) Crieff 2 Day Small Animal CPD Meeting pp125-144 Prof D
Gunn-Moore says "Since
hypophosphataemia can result in weakness and anaemia, it is important to
monitor phosphate levels whichever type of phosphate binder is chosen."
Try not to let your non-CKD cats eat food
containing phosphorus binders. This is particularly important for
kittens,
who need twice as much phosphorus each day as a healthy cat because they
are still growing.
However, if your healthy adult cats
eat a small amount of food containing binders occasionally (say once or
twice a week), this should not be a problem as long as you make sure that
most of the food they eat does not contain binders.
If you have to go to work each day and do not want to
separate your cats, one possible solution might be to leave out
therapeutic kidney dry food for all your cats to eat, but to give your
healthy cats normal food the rest of the time. Be guided by your vet.
If you are in the USA, you could also consider using
ConSeal AlH as discussed
below.
Please read above about which binder to use and why.
If you buy aluminium hydroxide, you may see an
expiration date on it. This is usually to comply with pharmacy laws, but
in practice, since aluminium hydroxide is a mineral that is mined from the
earth, it cannot really expire, so I would not worry too much about expiry
dates.
Be careful about your source for aluminium hydroxide.
Some people try to buy products that are not pharmaceutical grade, often
from ebay. These are not pure enough and are not suitable for CKD cats.
Sources USA
Aluminium Hydroxide USA
Rugby make an aluminium hydroxide gel product which you may come across on
various websites, but unfortunately it is mint flavoured which most cats
(apart from my Indie) don't like.
Loose Aluminium Hydroxide
Loose
aluminium hydroxide in gel or powder form is a popular choice because it
is odourless and tasteless, so is much easier to give. There are three
main generic brands available, Spectrum, Gallipot and PCCA.
Loose aluminium hydroxide used to be available in tubs
from a number of online pharmacies, but the only one which definitely
still sells it these days is Thriving Pets. Most local
compounding pharmacies should be able to order it for you, which may take a few days; it is fine to wait that long. You may be told that a prescription is required, but this is
not correct, the gel and powder formulations are over
the counter products.
Sells 200g (about 8 oz) of aluminium hydroxide dry
gel for US$47.95 plus shipping. They also sell
50g (a little under 2 oz) of aluminium
hydroxide for US$19.95. An oral suspension is also available for US$39.95.
Also sells aluminium hydroxide capsules, but these requires a prescription, which the other formulations do
not:
If you enter the word "tanya" (without the ") in the
promotional code box, you will receive a 10% discount on orders over
US$55. Shipping is free for orders over US$55 after the discount.
Phos-Bind
Phos-Bind is a brand of loose
aluminium hydroxide binder made by Rx Vitamins. It is available as
follows:
200g size (just over 7 ounces) with a scoop that is the
equivalent of half a teaspoon, and the scoop contains 500mg of aluminium
hydroxide.
35g size (just over 1 ounce) with a smaller
scoop that I understand contains 250mg of aluminium hydroxide, though I
have not been able to verify this as yet.
Sell
200g of Phos-Bind for US$38 with free shipping.
ConSeal AlH
ConSeal-AlH are aluminium
hydroxide 200 mg chews made by Bock Pharma. They come in a box of 28
individually wrapped chews. The recommended dose is 1-2 chews per 10 lbs
of cat given with meals. If you need to give less, the chews are semi-soft
so can be broken or cut into pieces. In this form they can be mixed with
food, but one member of
Tanya's CKD Support Group
found the chews very helpful for her cat who missed getting
treats, and gave them before her cat's meals. They could also be useful
for multi-cat households where you can give your CKD cat a ConSeal treat
whilst giving your other cats ordinary treats.
ConSeal AlH apparently has to be ordered through your vet, and a pack
costs about $20-$25.
If you buy your binders from your vet, you will often
be offered an aluminium hydroxide-based binder called
AlternaGel, but this
is peppermint flavoured, which most cats hate. AlternaGel
also contains
potassium citrate.
Amphojel, another product which vets sometimes stock,
comes in both unflavoured and peppermint flavoured
version, so check before you buy that you will be getting the
unflavoured one; most vets only seem to stock the
peppermint-flavoured version.
Fosrenol USA
Fosrenol can be expensive. Some people have found it
helpful to use the
Goodrx card to look for the cheapest pharmacy in their neighbourhood.
Doing this has enabled some people to purchase 90 tablets for US$300.92
from their local Wal-Mart.
sells thirty 1000mg Fosrenol tablets for US$364.77 or 50 for US$589.01.
You have to buy them from your local Costco pharmacy with a prescription
but you do not have to be a member of Costco to use their pharmacies.
Sell ten Fosrenol for US$99.95 or one hundred 500mg or 1000mg tablets for
US$999.95. A prescription is required. If you enter the word "tanya" (without the ") in the
promotional code box, you will receive a 10% discount on orders over
US$80. Shipping is free for orders over US$100 after the discount.
sells 50g of aluminium hydroxide powder for £19.50 with free shipping over
£50 otherwise shipping costs £2.99. It comes with a scoop that apparently
measures 0.5ml (which seems very small) and one level scoop holds 650mg of
aluminium hydroxide. I do not know anybody who has used this
yet.
An odourless
and flavourless phosphorus binder which used to be available
as 120 capsules, each containing 475mg of aluminium hydroxide.
Unfortunately they have been discontinued but your local phamracy may have
some in stock.
Don't say they are for a cat, or they may ask for a
prescription from your vet, whereas if you buy them for your own
indigestion, they are over the counter (though of course your vet should
be aware that you are using them).
A veterinary specials manufacturer that sells 50ml bottles of a 100mg per
1ml chicken-flavoured suspension for £48 plus £5 for shipping. This can only be ordered by
your vet.
US Sellers
If you import goods costing over £15 into the UK, you are liable for VAT
on the total cost of the order, including shipping costs. This can hold up
your order, because Royal Mail in particular will not deliver the goods
until you have paid any taxes and duty due. Therefore it may well be wiser
to order the 50g size, particularly if you need your binder quickly,
because this should come in at a cost of less than
£15. Alternatively, you could speak to your vet about using
another product such as Ipakitine while you wait for the aluminium
hydroxide to arrive from the USA.
in the USA will ship to the UK. Shipping should take 1-2 weeks.
200g (about 8 oz) of aluminium hydroxide dry gel costs US$47.95 plus
shipping.
50g (a little under 2 oz) costs US$19.95 plus shipping.
If you enter the word "tanya" (without the ") in the
promotional code box, you will receive a 10% discount on orders over US$55
(before shipping and other costs).
is a link for a Phos-Bind seller in the USA, and if you click on the See
All Buying Options for somebody prepared to ship to the UK, you may get
lucky.
Ipakitine UK
These products are usually available from local vets and Amazon.
sells aluminium hydroxide powder for CAN175 for 454g (1 lb) or CAN$26 for
35g. No prescription is
required. It comes with a scoop which I understand is the same as a
teaspoon and one scoop contains 1200mg.
Sells 100g of aluminium hydroxide, you
can
contact
them to
check the current price, but for reference, in November 2019 one member ofTanya's CKD Support Group paid CAN$20
plus CAN$12 for shipping. Unfortunately this product is being discontinued
so may no longer be available by the time you read this.
In the USA sells 200g for US$26.57. Total cost including shipping to
Canada is around CAN$106.
Sources Europe
Aluminium Hydroxide Europe
If you live in a country where compounding is available, most compounding
pharmacies will be able to assist you.
Ipakitine Europe
This is widely available in most European countries, from vets, online pet
supply stores or Amazon.
Sources - Australia and New Zealand
Alu-Tabs, made by iNova
Pharmaceuticals, are probably your best bet. They come in 600mg tablets
rather than a powder, but I imagine you could crush them. They should be
available over the counter in pharmacies, though your pharmacist may not
realise they are there. Don't say they are for a cat, or they may ask for
a prescription from your vet, whereas if you buy them for your own
indigestion, they are over the counter.
TREATING YOUR CAT WITHOUT VETERINARY ADVICE CAN BE
EXTREMELY DANGEROUS.
I have
tried very hard to ensure that the information provided in this website is
accurate, but I am NOT a vet, just an ordinary person who has lived
through CKD with three cats. This website is for educational purposes
only, and is not intended to be used to diagnose or treat any cat. Before
trying any of the treatments described herein, you MUST consult a
qualified veterinarian and obtain professional advice on the correct
regimen for your cat and his or her particular requirements; and you
should only use any treatments described here with the full knowledge and
approval of your vet. No responsibility can be accepted.
If your cat
appears to be in pain or distress, do not waste time on the internet,
contact your vet immediately.
This site was
created using Microsoft software, and therefore it is best viewed in
Internet Explorer. I know it doesn't always display too well in other
browsers, but I'm not an IT expert so I'm afraid I don't know how to
change that. I would love it to display perfectly everywhere, but my focus
is on making the information available. When I get time, I'll try to
improve how it displays in other browsers.
This site is a labour of love. Please do not steal from me by taking credit for my work.
If you wish to
link to this site, please feel free to do so. Please make it clear that
this is a link and not your own work. I would appreciate being informed of
your link.
