TANYA'S

COMPREHENSIVE GUIDE TO

FELINE CHRONIC KIDNEY DISEASE

 

 

NAUSEA, VOMITING, LOSS OF APPETITE AND EXCESS STOMACH ACID

 

ON THIS PAGE:


Causes of Nausea, Vomiting and Appetite Loss

Symptoms


Treatments:


Step 1: Simple natural treatments: raising the food bowl, feeding before bedtime and slippery elm bark


Step 2: Acid Blockers: famotidine (Pepcid AC, ranitidine (Zantac 75, cimetidine (Tagamet) and omeprazole (Prilosec)


Step 3: Other treatments: ondansetron (Zofran), maropitant (Cerenia) and metoclopramide (Reglan)


 

 

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Nausea, Vomiting, Appetite Loss and Excess Stomach Acid


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Fluid and Urinary Issues (Fluid Retention, Infections, Incontinence, Proteinuria)


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Home > Key Issues > Nausea, Vomiting, Appetite Loss and Excess Stomach Acid

 


Overview


  • Nausea, vomiting and loss of appetite are some of the most common problems in CKD cats.

  • There are a variety of possible causes, and a cat may have more than one reason for showing these symptoms.

  • Fortunately, in most cases there are treatments which can help make the cat feel much more comfortable, but in order to know which treatment would work best, you need to know the most likely cause in your cat's case.

  • Toxins caused by the kidney disease, including excess stomach acid, are one of the most likely culprits in cats with creatinine over 3 mg/dl (USA) or 265 mmol/L (international), though they can also be a problem in cats with lower creatinine levels. There are a number of treatments that can help.

  • If your cat continues to have problems despite being treated for excess stomach acid and any other possible causes, there are other treatments available which can help control nausea and vomiting.

  • Please note, excess stomach acid is not the same thing as metabolic acidosis.


Causes of Nausea, Vomiting and Loss of Appetite                                             Back to Page Index


 

Common Causes


Unfortunately, there are a large number of possible causes of nausea, vomiting and loss of appetite in CKD cats. It can therefore be confusing trying to decide what might be the cause in your cat's case. To help you narrow it down, I would scan through the list of symptoms on the Index of Symptoms and Treatments page to see if any of them look familiar.

 

Alternatively, the list below outlines some of the possible causes of nausea, vomiting and loss of appetite. If you already know that your cat has a particular problem, say, high phosphorus levels, you can click on the appropriate link where you will find more information on other symptoms associated with that condition, which may help you narrow down the cause:

Ask your vet to rule out any of these causes or to treat them if they are present. Treating any that are present should not only stop the vomiting and appetite loss and help your cat feel more comfortable, it may in some cases (e.g. controlling high phosphorus levels) also help slow the progression of the CKD.

 

Toxins, Including Excess Stomach Acid


Even if you rule out or treat the above causes, your cat may still continue to have problems with vomiting, nausea and appetite loss, so the chances are you need to read this page even if your cat has some of the above problems too. Take a look at the list of symptoms below and see if they sound familiar - most people find they do.

 

In such cases, the problem may be caused by toxins. As the kidneys gradually lose their ability to regulate and remove waste products effectively, these waste products build up in the blood. This is called uraemia and can make a cat feel very unwell. You can read more about uraemia here.

 

Although BUN is not itself a toxin, there is a correlation between it and other toxins which are less easy to measure. Therefore, the higher your cat's BUN or urea level, the higher the overall toxin load will be, and the more likely it is that s/he will feel sick and vomit.

 

CKD cats may also have problems with excess stomach acid. Gastrin is a gastrointestinal hormone which stimulates the secretion of gastric acid, which helps the stomach digest food. The kidneys are responsible for the excretion of gastrin, but in CKD this function may not work so well, resulting in the gastrin remaining in the stomach and potentially stimulating the production of too much gastric acid. Feline CKD: Current therapies - what is achievable? (2013) Korman R & White J Journal of Feline Medicine and Surgery 15(S1) pp29–44 says "Gastrin is excreted by the kidneys and the concentration increases with CKD progression, increasing gastric acidity and the risk of ulceration." Excess stomach acid can make a cat feel very unwell. In severe cases stomach ulcers may develop, which may cause gastrointestinal bleeding.

 

A more recent study, Relationship among serum creatinine, serum gastrin, calcium-phosphorus product, and uremic gastropathy in cats with chronic kidney disease (2014) McLeland SM, Lunn KF, Duncan CG, Refsal KR & Quimby JM Journal of Veterinary Internal Medicine 28(3) pp827-37 compared CKD cats with healthy cats. They found that 84% of the CKD cats exhibited loss of appetite and 45% exhibited vomiting, but although the CKD cats did have higher levels of gastrin compared to the healthy cats, there did not appear to be any correlation with the severity of the CKD. The study states "Gastrointestinal signs in these animals may not necessarily be the result of gastric lesions such as gastric ulceration and inflammation, but perhaps the consequence of circulating uremic toxins interacting with the chemoreceptor trigger zone in the brain."

 

Chronic use of maropitant for the management of vomiting and inappetance in cats with chronic kidney disease: a blinded placebo-controlled clinical trial (2014) Quimby JM, Brock WT, Moses K, Bolotin D, Patricelli K Journal of  Feline Medicine & Surgery 21. pii: 1098612X14555441. [Epub ahead of print] says "Interestingly, the exact mechanism of why CKD cats suffer from decreased appetite and vomiting is not currently known. Gastrin hormone that is responsible for stomach acid production is elevated in CKD cats; however, increased stomach acidity and stomach ulceration have not been document [sic] in humans or cats with CKD.  It is suspected that CKD cats have an increase in toxins referred to as uremic toxins that trigger the vomiting center (chemoreceptor trigger zone of the area postrema) in their brains."

 

Whatever the cause, a CKD cat who exhibits the symptoms listed below needs help. Generally speaking, these will be cats with creatinine over 3 mg/dl (US) or 265 mmol/L (international) (IRIS stages 3 or 4). Feline CKD: Current therapies - what is achievable? (2013) Korman R & White J Journal of Feline Medicine and Surgery 15(S1) pp29–44 says "Cats in CKD stages 3-4 often demonstrate gastrointestinal signs of uraemia (eg, inappetance, nausea, vomiting, stomatitis, gastrointestinal ulceration, diarrhoea, colitis) and addressing these may improve quality of life."

 

If your cat has relatively low kidney bloodwork values (creatinine of 2.5-3 mg/dl US, 200-300 mmol/L international) but nevertheless seems to vomit a lot, it might possibly be because of CKD-related toxins, but I would also ask your vet to rule out pancreatitis.

 


Symptoms                                                                                                           Back to Page Index


 

There is no test as such for toxins, but these are some of the symptoms you might see (though some of these may also be due to other causes, as mentioned under each category):

 

Loss of Appetite


Loss of appetite is very common in CKD cats, and is often linked to excess stomach acid. Human CKD patients have reported that their sense of smell and sometimes taste are impaired; this is thought to be caused by uraemic toxins, and probably occurs in cats too.

 

There are several other possible causes of lack of appetite, including dehydration, high phosphorus levels, anaemia, fluid retention or heart problems, crashing, metabolic acidosis, mouth ulcers, the use of antibiotics, constipation or hyperthyroidism medicationDental problems may also cause appetite loss.

 

Cats who do not eat are at risk of developing a potentially life-threatening condition known as hepatic lipidosis; Mar Vista Vet has more information about this. Therefore, it is important to try to find the cause of the inappetance and treat it as quickly as possible. 

 

Nausea


Nausea can be hard to detect, though it is often manifested in a lack of appetite. The cat may also lie scrunched up, looking uncomfortable. It is perfectly possible for a cat to have nausea but not to vomit.

 

High phosphorus levels, dehydration or anaemia may also cause nausea.

 

Vomiting


CKD cats often vomit. Vomiting may be seen alone or in conjunction with the other symptoms in this section. Many cats with excess stomach acid or uraemia vomit regularly without treatment.

 

Sometimes there may be blood in the vomit - bright red blood is fresh blood, whilst older blood looks like ground coffee grains. This may be a sign of mouth ulcers or of gastrointestinal bleeding, but you should contact your vet immediately if you see this symptom - our George, a non-CKD cat, vomited old blood as the first symptom of severe liver disease.

 

Cats who vomit a lot are more likely to become dehydrated.

 

There is a difference between vomiting and regurgitation. Vomiting is usually accompanied by a lot of abdominal movement, whereas regurgitation happens suddenly and with less warning. Vomiting means the cat is emptying the stomach, whereas regurgitation is where food has not yet reached the stomach but is being ejected from the oesophagus more or less intact, often because of eating too fast or hairballs. Regurgitation is often sausage-shaped. Veterinary Partner explains the difference and has videos showing vomiting versus regurgitation.

 

Cats who vomit immediately after eating may have a gastric motility problem - ranitidine may help with this.

 

Occasionally vomiting is caused by constipation, particularly if your cat vomits before, during or immediately after using the litter tray. 

 

If you are giving your cat sub-Q fluids and s/he regularly vomits after fluids, this may because of the type of fluid used.

 

Washington State University College of Veterinary Medicine has information on vomiting.

Coco's page has practical advice from a CKD parent.

Vet Info has information on vomiting.

Why so many vomiting cats? Getting the diagnosis (2011) is a presentation by Dr S Little to the 36th World Small Animal Veterinary Association World Congress with a flow chart for narrowing down the cause of the vomiting.

Vomiting cat cases: you can figure them out (2015) Dr D Zoran NAVC/WVC Proceedings discusses how to narrow down the cause of vomiting and the possible treatments.

Diagnosis and management of acute and chronic vomiting in dogs and cats (2007) is a paper by Dr TR Tams.

Pet Place has tips on caring for a vomiting cat.

Pet Place discusses vomiting.

 

Vomiting White Foam


Vomiting does not just include food - the classic symptom of excess stomach acid is to vomit clear or white foam. This is often one of the first signs that people notice when their cat is developing CKD.

 

Vomiting Water


Sometimes CKD cats drink a lot on water in one go, them vomit all or most of it up shortly afterwards. This may be a sign of excess stomach acid. It is possible that the cat has an urge to drink before vomiting so as to dilute the stomach acid.

 

Lip Licking


This can be a sign of nausea and excess stomach acid. It may also be a sign of dehydration. Less commonly, it can be a sign of anaemia. In rare cases it may be caused by longer term (over three months) use of metoclopramide (Reglan)

 

Teeth Grinding


Cats who grind their teeth may have excess stomach acid. Dental problems are another possible cause. It may also be a sign of dehydration. Very occasionally, this might be a sign of "rubber jaw", caused by a condition related to CKD called secondary hyperparathyroidism.

 

Animal Dental Center of Milwaukee and Oshkosh discusses the various causes of teeth grinding in cats.

Youtube has a video of a cat grinding his/her teeth.

 

Hoarseness


CKD cats may occasionally become rather hoarse because of acid reflux caused by excess stomach acid. 

 

In some cases hoarseness may be a sign of low potassium levels. Hoarseness is also sometimes seen in cats with hyperthyroidism. If accompanied by coughing, consider the possibilities of fluid retention or heart problems.

 

Drooling


Drooling cats may have excess stomach acid. Dental problems or mouth ulcers may also  cause drooling. Manhattan Cat Specialists have more information about drooling.

 

Eating Grass


Cats commonly eat grass in order to help themselves vomit. They often do this if they want to bring up a hair ball, and this is sometimes also the reason why CKD cats eat grass. However, CKD cats do tend to feel nauseous generally, because of the disease rather than because of hair balls, and if you feel nauseous, you may feel a little better if you can actually vomit. Therefore CKD cats who feel nauseous may eat grass in order to make themselves vomit. It is normally fine to allow your CKD cat to eat grass, as long as it has not been treated with pesticides.

 

Yawning and Howling


These may sometimes be symptoms of excess stomach acid. Howling may have other causes (see Index of Symptoms and Treatments). 

 

Hunched over Water Bowl


This can be a sign of nausea and excess stomach acid. Occasionally it is a sign of dehydration

 

Playing with Water


Some cats like to play with their water bowls from an early age, but some CKD cats develop a bit of an obsession with water, and may play with their water bowl or paw at the water. You may see other new behaviours, such as drinking from showers or gutters, or hanging around sinks and begging for fresh running water from the tap. All these types of behaviour may indicate excess stomach acid. Other possible causes include dehydration or diabetes.  

 

Sniffing or Licking or Looking at Food, then Walking Away


The cat may approach the food bowl and sniff or lick the food, then walk away. This is a pretty classic sign of excess stomach acid, but it may also indicate mouth ulcers.

 

Pawing at the Mouth


The most common reason for this is dental problems, but occasionally it is a sign of excess stomach acid.

 

Increased Drinking


Increased drinking is common in CKD cats because they usually have problems maintaining hydration. However, it can also be a symptom of excess stomach acid. In some cases it may indicate diabetes.

 

Licking Gravy Only


The cat may lick the gravy only and leave any solid food behind. However, this may not indicate excess stomach acid in all cats, only if it is a new behaviour - my cats do this all the time and they are healthy, they just prefer pâté-type foods. Another possible cause is dental problems.

 

Sitting Hunched Up


Since cats with excess stomach acid have sore tummies, they may sit in a hunched up, uncomfortable position. In the worst case, this may indicate crashing, but only if you also see the symptoms described there.

 


Treatments                                                                                                          Back to Page Index


 

Simple Natural Treatments Acid Blockers Other Treatments

 

Although it is not possible to test for toxins, if your cat is showing any of the symptoms described above (e.g. vomiting white foam), it is usually worth trying treatments and seeing if your cat feels better. Many people find simply using the appropriate treatments on this page (with their vet's approval, of course) helps their cats to feel noticeably better. Feline CKD: Current therapies - what is achievable? (2013) Korman R & White J Journal of Feline Medicine and Surgery 15(S1) pp29–44 says "Cats in CKD stages 3–4 often demonstrate gastrointestinal signs of uraemia (eg, inappetance, nausea, vomiting, stomatitis, gastrointestinal ulceration, diarrhoea, colitis) and addressing these may improve quality of life."

 

Although many CKD cats benefit from the treatments described below, the best treatment depends upon the cause of the problem. For example, many cats with anaemia lose their appetites, and the treatments on this page will not help with that, you need to treat the anaemia. You can check the Index of Symptoms and Treatments page for information on treatments for the other possible causes mentioned above.

 

The International Renal Interest Society (2013) recommends treating reduced appetite, vomiting or nausea "with a proton pump inhibitor (e.g., omeprazole) and an antiemetic (e.g., maropitant or ondansetron). However, further investigations are needed on the use of these drugs to determine whether they are useful for managing gastrointestinal disturbances in cats with CKD and uraemia." These treatments are all discussed below.

 

I recommend a staged approach, and so does Feline CKD: Current therapies - what is achievable? (2013) Korman R & White J Journal of Feline Medicine and Surgery 15(S1) pp29–44, which says "Antiemetic agents are typically added in a stepwise (i.e., one at a time) progression dependent on patient response. The authors typically use omeprazole with maropitant or ondansetron if inappetance or nausea persist….and ranitidine is used in cats that demonstrating signs of ileus (e.g., identified on ultrasound)."

 

How I treat uremic crises in dogs and cats with chronic kidney disease (2009) is a presentation by Dr D Polzin to the 34th World Small Animal Veterinary Association World Congress which discusses various treatments.

Current approaches to vomiting in cats and puppies (2013) Pfizer Roundtable Discussion has some information on how to treat vomiting in cats.

 

Here is a possible staged treatment plan for you to discuss with your vet:

 

Step 1: Simple Natural Treatments


The simple natural treatments come first, because they are simple, effective, inexpensive, and can be done immediately and without a vet visit (though please inform your vet if you wish to try slippery elm bark). For some cats, especially those in early stage CKD, these are the only treatments they need:

 

Step 2: Acid Blockers


If the treatments in Step 1 don't seem to be helping after a couple of days, move onto the acid blockers, which are a group of medications commonly used to control excess stomach acid. You can use these in conjunction with the natural treatments.

 

Step 3: Other Treatments


These medications are usually very effective for nausea and vomiting. They can help cats who do not respond fully to the treatments in Steps 1 and 2, or whose CKD is more advanced. They may also be useful to help cats with additional issues, such as gastric mobility, or cats with concurrent pancreatitis or IBD. They can usually be used in conjunction with the medications outlined above:

It is usually safe to use more than one of these treatments at the same time, e.g. slippery elm bark and famotidine, but check with your vet first. Don't use Pepto-Bismol or  antacids such as Tums or Mylanta.

 


Natural Treatments                                                                                                                       Back to Page Index


The beauty of these treatments is that they need little effort, are not particularly invasive and require very little outlay, yet for some cats they are extremely effective. I therefore recommend trying them to see if they help. If they are going to help, you would normally see a difference (e.g. reduced vomiting) within a couple of days.

Raising Your Cat's Bowls


Normally a cat eats with the mouth lower than the stomach, but in CKD cats this can cause stomach acid to enter the oesophagus and trigger acid reflux. Keeping the cat's food and water bowls higher than the stomach can help minimise this problem and may encourage your cat to eat and drink more.

 

Standing bowls on an upside-down flower pot can often create the correct height for your cat and provide a sturdy base: choose a flower pot of the appropriate height for your cat. Some pet stores also sell food dishes on legs, which are approximately 6 inches (15cm) high.

 

Classy Cat Dishes sell raised stoneware bowls for about US$40. You can also find them on Amazon. I have had these for years, and they are still in great shape and my cats love them. My cats do not have CKD, but I have noticed they eat more if I feed them from these bowls. To the left you can see my silly kitten using his classy cat dish in his own inimitable way - he did finally get the hang of it!

Drs Foster & Smith sell a cast iron raised food bowl stand from US$17.99. They also sell some other raised bowls.

Amazon UK sells some raised bowls which at least one member of my support group has used, though I think these would be too deep for some cats, especially Persians.

The Art of Doing Stuff has ideas on making your own raised bowls, though I think the ones she uses are too deep for cats.

 

 

Feeding Before Bedtime


You may find that your cat has more stomach upsets at night which cause vomiting during the night or first thing in the morning. This happens because if a cat goes a long time without eating, the excess stomach acid has more time to attack the stomach lining.

 

Try to ensure that your cat eats before bedtime in order to prevent this - keeping food constantly in the stomach means the acids are more likely to attack the food rather than the stomach lining. It may also be worth setting up an automated feeder on a timer with food in it to keep your cat supplied with food throughout the night. There are links to such feeders here.

 

Slippery Elm Bark


If you wish to pursue natural methods of controlling stomach acid and the accompanying vomiting, nausea and loss of appetite, a herbal remedy called slippery elm bark (SEB) is often very effective. It soothes the digestive tract, so it can also help with both constipation and diarrhoea. The Holistic Treatments page has more detailed information on SEB. Please inform your vet if you wish to use slippery elm bark.

 

 


Use of Acid Blockers                                                                                                                   Back to Page Index


 

This is a group of medications which can be most effective in controlling excess stomach acid, which in turn can greatly reduce vomiting and nausea and increase appetite. Omeprazole is becoming more popular and seems to be very effective. Although there is little evidence that the histamine H2 antagonists work, in practice they do seem to help the vast majority of cats, and many people still use them, not least because they are cheap and easily available over the counter in most countries (though please do not use them without your vet's permission).

Histamine H2 Antagonists


Famotidine (Pepcid AC), ranitidine (Zantac 75) and cimetidine (Tagamet) are commonly thought of as antacids, although in fact technically speaking they are histamine H2 antagonists that block the production of stomach acid rather than neutralise it. Because they are long-acting, they are generally a good choice for treating stomach acid problems. In Current concepts for the management of chronic renal failure in the dog and cat - early diagnosis and supportive care (2005) Presentation to the 30th World Congress of the World Small Animal Veterinary Association, Dr Sherry Sanderson mentions that it is generally recommended to use such treatments once creatinine is over 3 mg/dl (USA) or 265 mmol/L (international).

 

Although these medications can be purchased over the counter, please do NOT give them without first discussing them with your vet, particularly if your cat has advanced CKD, because they are excreted by the kidneys so may not be appropriate. Avoiding Adverse Drug Reactions (2001), a paper presented by Lauren Trepanier  to the World Small Animal Veterinary Association World Congress 2001, mentions that it is wise to reduce the dose of these medications in CKD cats (scroll to the end).

 

Once you start giving these medications, it is usually better to continue giving them regularly even if your cat appears better, so the excess stomach acid cannot start building up again.

 

Famotidine (Pepcid AC)


Famotidine (Pepcid AC) is the most commonly used medication for feline CKD-related stomach acid problems in the USA, and it is a very effective treatment for excess stomach acid. As a side effect, famotidine may reduce parathyroid hormone levels in CKD patients. Famotidine reduces serum parathyroid hormone levels in uremic patients (1991) Arik N, Arinsoy T, Sayín M, Taşdemir I, Yasavul U, Turgan C, Caglar S Nephron 59(2) p333 explains more about this. I would not use famotidine to treat elevated PTH levels only.

Famotidine Formulations


Famotidine is available as a generic or, in the USA, under the brand name Pepcid AC. Famotidine may be sold under a different name in your country (e.g. Amfamox, Famox or Pepcidine in New Zealand and Australia). General Medical shows which trade names famotidine is known by in various countries. Famotidine is available in the USA as a tablet, oral suspension or as an injectable.

 

Famotidine Tablets


USA

Pepcid AC (Regular Strength) in the USA contains 10mg of famotidine. If you opt for the brand name, there are quite a few Pepcid products available so make sure you buy the correct one. You need Pepcid AC 10mg but not the chewable type, and not Pepcid Complete, both of which have some ingredients which make them unsuitable for CKD cats. There is also a new version called Pepcid Maximum Strength, which is the same as Pepcid AC except that it contains twice as much famotidine, so be very sure you have the correct strength (10mg tablets).

 

Using generic famotidine is acceptable, but make sure it is the correct strength and that it does not contain any additional ingredients.

 

UK

Unfortunately, Pepcid AC has been discontinued in the UK, having been replaced by PepcidTwo. PepcidTwo contains magnesium and calcium in addition to famotidine, so it is not suitable for CKD cats.

 

Famotidine does exist in generic form and is available from chemists, but only in 20mg size, which could be difficult to cut; plus it requires a prescription from your vet.

 

If you really want to use famotidine, it is sometimes available from Amazon UK in the 10mg strength at prices ranging from £5-65 (search for Pepcid AC or famotidine). You can also obtain it in compounded cat-sized form from The Specials Laboratory - 90 2.5mg capsules cost £93.79 plus VAT and shipping costs of around £12.50. They also sell 100ml of famotidine 2.5mg per ml for £91.89, with a 90 day expiry from manufacture. If you don't want to pay those prices, I would consider using ranitidine instead.

 

Famotidine Oral Suspension


Famotidine is also available as an oral suspension (liquid) in the USA. It is widely available from compounding pharmacies, and usually costs around US$20 for a month's supply.

 

Thriving Pets sells a 10mg/ml oral suspension (liquid) version of famotidine in a 10ml size for US$19.95. If you want to give the usual famotidine dose of 2.5mg (see below), you would give 0.25ml, so this product contains 40 doses altogether. This product has a short shelf life of 30 days (including delivery). If you enter the word "tanya" (without the ") in the promotional code box, you will receive a 10% discount on orders over US$100. Shipping is free for orders over US$100 after the discount.

 

Famotidine Injectable


Some people prefer to use this because famotidine tastes very bitter in pill or oral suspension form. You can use the injectable either by injecting it directly into your cat, or if your cat is on sub-Qs, by adding it to the injection port of your IV line.

 

There are two types of famotidine injectable. There is a 10mg/ml strength without preservative, which is available in 2ml vials. Because it contains no preservatives, this has a short shelf life (it is intended for single use in humans). There is also  a 10mg/ml strength available in a 20ml size vial. This contains a preservative and can be re-used, though it needs to be shipped chilled and should be kept in the fridge after you receive it. It is safe to take it out of the fridge about 30 minutes before using it so it can warm up a little before use.

 

Injectable famotidine is often out of stock so you may have to search for it.

 

Thriving Pets sells the 10mg/ml injectable form of famotidine in a 20ml size for US$29.95. If you want to give the usual famotidine dose of 2.5mg, you would give 0.25ml, thus the 20ml size contains 80 doses altogether. If you enter the word "tanya" (without the ") in the promotional code box, you will receive a 10% discount on orders over US$100. Shipping is free for orders over US$100 after the discount.

 

Famotidine Dosages


Famotidine is excreted by the kidneys, and cats with CKD cannot process it as efficiently as healthy cats, so it may accumulate in the cat's body and cause problems. The US Food & Drug Administration has information about the need to reduce the normal dose in (human) CKD patients. Avoiding Adverse Drug Reactions (2001), a paper presented by Lauren Trepanier to the World Small Animal Veterinary Association World Congress 2001, mentions that it is wise to do the same with CKD cats (scroll to the end).

 

Below are suggestions for famotidine dosages for CKD cats, but be guided by your vet. You should only use famotidine with your vet's approval. Do not start with the maximum dose, it could be risky.

 

Starting dose:

2.5 mg once every other day

i.e. quarter of a 10mg tablet once every two days e.g. on Mon, Wed, etc.

Intermediate dose (if starting

dose does not seem to be helping):

2.5mg once a day

i.e. quarter of a 10mg tablet once a day

Maximum dose:

2.5mg twice a day

i.e. quarter of a 10mg tablet twice a day, 5mg a day in total

 

If you are only giving famotidine once a day, I would recommend doing so at bedtime because this seems to help cats who vomit at night or first thing in the morning. Famotidine tastes quite bitter and can make cats foam at the mouth, so you may find it easier to give it in a gelatine capsule (gelcap) or to use the injectable form (see above). It usually takes effect pretty quickly, within a couple of days for most cats.

 

Some people find that after a while, famotidine seems to be less effective. If you are using a low dose, increasing the dose as outlined above might help. Alternatively, you could ask your vet about switching to ranitidine.

 

Famotidine Side Effects and Interactions


The most common side effects in humans are constipation or diarrhoea.

 

Some cats, particularly those with high bloodwork (creatinine over 5 mg/dl (USA) or 450 mmol/L (international)), do not seem to do well on famotidine, perhaps because their kidneys cannot excrete it efficiently as described above. These cats may in fact exhibit increased vomiting and appetite loss when given it - this happened to our Thomas. Drugs mentions how an overdose may cause vomiting. If your cat's vomiting and appetite loss do not improve after two days of using famotidine, ask your vet about switching to ranitidine.

 

Famotidine may adversely affect cats with existing heart rhythm problems. In such cases you may wish to ask your vet about using ranitidine instead.

 

Medicine Net mentions that famotidine may cause anaemia in humans. Web MD reports that human CKD patients on famotidine may exhibit abnormal levels of drowsiness.

 

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 Conference,  Dr D Chew 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 calcium-based phosphorus binders such as Ipakitine or Pronefra, I would discuss the situation with your vet.

 

Famotidine can interfere with antibiotics in the cephalosporin family such as cefovecin (Convenia), so you should separate the two treatments by two hours. H2-antagonist cephalosporin interactions (2003) Ali A Thesis states "These interaction studies with H2-receptor antagonists in gastric as well as blood pH revealed that simultaneous use of these drugs depressed the availability of the antibiotic as well as cimetidine, ranitidine and famotidine." Plumb's Veterinary Drug Handbook does not mention cefovecin (Convenia) specifically, but does mention that taking other members of the cephalosporin family with food may offset the reduced absorption of the antibiotic.

 

Famotidine may reduce the absorption of vitamin B12 from food. Proton pump inhibitor and histamine H2 receptor antagonist use and vitamin B12 deficiency (2013) Lam JR, Schneider JL, Zhao W & Corley DA Journal of the American Medical Association 310(22) pp2435-2442 found that in humans "gastric acid inhibitor use was significantly associated with the presence of vitamin B12 deficiency." Therefore if you are using famotidine, it might be worth supplementing vitamin B12.

 

I used to recommend giving famotidine at least two hours apart from sucralfate (Carafate or Antepsin) or metoclopramide (Reglan), because, according to Plumb's Veterinary Drug Handbook, these other medications could bind with the famotidine and thereby reduce its effectiveness. However, the most recent edition of Plumb's does not mention this requirement, so it appears that you do not need to separate famotidine from these other medications after all.

 

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." Plumb's does still recommend separating famotidine from phosphorus binders and ACE inhibitors. 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.

 

Veterinary Partner has more information on famotidine, and mentions how it may adversely affect cats with heart rhythm problems.

Pet Place has more information about famotidine (no need to register to read the article, just click on Close at the bottom of the pop-up).

 

Ranitidine (Zantac 75)


Another popular over the counter histamine H2 antagonist is ranitidine (trade name is Zantac 75), which works in a similar way to famotidine. Some people prefer to use ranitidine, especially if their cat has experienced increased vomiting with famotidine, as happens with a small number of cats (usually those with creatinine over 5 mg/dl USA or 450 mmol/L international).

 

Ranitidine helps with gut motility. According to Feline constipation, obstipation, and megacolon: prevention, diagnosis, and treatment (2001) Washabau R Presentation to the World Small Animal Veterinary Association World Congress, ranitidine may also help some cats with constipation.

 

Ranitidine Formulations


 

Ranitidine Tablets


Ranitidine tablets are widely available, either as a generic or under the trade name Zantac 75. In the USA they cost around US$20 for 80 75mg tablets. Zantac OTC has regular coupons available. In the UK they usually cost around £1.20 for 12 75 mg tablets Unfortunately in Australia it appears the smallest size available is now 150 mg, which is very difficult to divide into cat-sized doses.

 

The main problem with ranitidine tablets is dividing them up into cat-sized dosages - they usually have to be cut into eighths (assuming you are using the 75mg size). If you find it hard to cut the pill into eight, you could try dissolving it in water and giving an eighth of the resulting mixture via syringe.

 

Ranitidine Oral Suspension


There is also a liquid (syrup) form of ranitidine in the USA, but this is peppermint flavoured, so not many cats would like it, plus you need a prescription for it. However, I understand you can obtain it in a beef flavoured compounded suspension from Thriving Pets. If you enter the word "tanya" (without the ") in the promotional code box, you will receive a 10% discount on orders over US$100. Shipping is free for orders over US$100 after the discount.

 

Ranitidine Injectable


There is also a prescription only injectable form of ranitidine obtainable from most US pharmacies (they may need to order it for you, and it seems to go out of stock quite regularly in recent times).

 

Injectable ranitidine comes in a 25mg/ml strength, usually in a 6ml vial. You can either inject this directly into your cat, or  if your cat is on sub-Qs, add it to the injection port of your IV line. A possible dose is 0.3ml twice a day, but ask your vet. Injectable ranitidine usually needs to be refrigerated but it is safe to take it out about 30 minutes before using it so it can warm up a little before use.

 

Thriving Pets sells injectable ranitidine. If you enter the word "tanya" (without the ") in the promotional code box, you will receive a 10% discount on orders over US$100. Shipping is free for orders over US$100 after the discount.

 

Ranitidine Dosages


One reason why people may decide not to use ranitidine is that it usually has to be given twice a day, whereas famotidine is usually only given once every other day, or occasionally once a day.

  • The usual dose is 0.25 to 1.00 mg per pound (0.5 - 2.00 mg per kg) every 8-12 hours, though most people find twice a day is fine.

  • You therefore would give a 10lb (4.5kg) cat 2.5 - 10 mg twice a day.

  • The standard size pill is 75mg, so for a 10 lb (4.5kg) cat who is getting the higher dose, it is usually easiest simply to give an eighth of a tablet twice a day (i.e. 9.375 mg, or a little under 10 mg).

  • Some people give up to twice this amount, but as with famotidine, I suggest starting low and increasing the dose if necessary since ranitidine is also excreted by the kidneys. Be guided by your vet.

Ranitidine tastes quite bitter and can make cats foam at the mouth, so you may find it easier to give it in a gelatine capsule (gelcap). Many people prefer to give the second dose of the day at bedtime because this seems to help cats who vomit at night or first thing in the morning. It usually takes effect pretty quickly, within a couple of days.

 

As with famotidine, some people find that after a while, ranitidine seems to be less effective. Speak to your vet about either increasing the dose or frequency or using another treatment as well as or instead of the ranitidine.

 

Ranitidine Side Effects and Interactions


Ranitidine may cause vomiting and diarrhoea in some cats.

 

Plumb's Veterinary Drug Handbook recommends separating ranitidine from phosphorus binders but The Merck Veterinary Manual says ranitidine can be given at the same time as low doses of phosphorus binders. It does recommend separating ranitidine from sucralfate (Carafate or Antepsin)

 

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 Conference,  Dr D Chew 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 ranitidine in addition to calcium-based phosphorus binders such as Ipakitine or Pronefra, I would discuss the situation with your vet.

 

Ranitidine can interfere with antibiotics in the cephalosporin family such as cefovecin (Convenia), so you should separate the two treatments by two hours. H2-antagonist cephalosporin interactions (2003) Ali A Thesis states "These interaction studies with H2-receptor antagonists in gastric as well as blood pH revealed that simultaneous use of these drugs depressed the availability of the antibiotic as well as cimetidine, ranitidine and famotidine." Plumb's Veterinary Drug Handbook does not mention cefovecin (Convenia) specifically, but does mention that taking other members of the cephalosporin family with food may offset the reduced absorption of the antibiotic.

 

Ranitidine may reduce the absorption of vitamin B12 from food. Proton pump inhibitor and histamine H2 receptor antagonist use and vitamin B12 deficiency (2013) Lam JR, Schneider JL, Zhao W & Corley DA Journal of the American Medical Association 310(22) pp2435-2442 found that in humans "gastric acid inhibitor use was significantly associated with the presence of vitamin B12 deficiency." Therefore if you are using ranitidine, it might be worth supplementing vitamin B12.

 

It is also advisable to separate ranitidine from ACE inhibitors such as benazepril (Fortekor), but if this is difficult for you, e.g. because of work commitments, just do the best you can.

 

Pet Place has more information about ranitidine (no need to register to read the article, just click on Close at the bottom of the pop-up).

 

Cimetidine (Tagamet)


You may be offered another drug in this family called cimetidine. Cimetidine has many more drug interactions than either famotidine or ranitidine, including with amlodipine (a calcium channel blocker used to treat heart disease or high blood pressure), and diazepam (Valium), which is sometimes used as an appetite stimulant. It also has the most marked rebound effect (a temporary increase in stomach acid) if it is stopped. I would therefore suggest using famotidine or ranitidine instead. 

 

If you do use cimetidine, The Merck Veterinary Manual recommends separating it from phosphorus binders and from sucralfate (Carafate or Antepsin).

 

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 Conference,  Dr D Chew 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 cimetidine in addition to calcium-based phosphorus binders such as Ipakitine or Pronefra, I would discuss the situation with your vet.

 

Cimetidine can interfere with antibiotics in the cephalosporin family such as cefovecin (Convenia), so you should separate the two treatments by two hours. H2-antagonist cephalosporin interactions (2003) Ali A Thesis states "These interaction studies with H2-receptor antagonists in gastric as well as blood pH revealed that simultaneous use of these drugs depressed the availability of the antibiotic as well as cimetidine, ranitidine and famotidine."

 

Cimetidine may reduce the absorption of vitamin B12 from food. Proton pump inhibitor and histamine H2 receptor antagonist use and vitamin B12 deficiency (2013) Lam JR, Schneider JL, Zhao W & Corley DA Journal of the American Medical Association 310(22) pp2435-2442 found that in humans "gastric acid inhibitor use was significantly associated with the presence of vitamin B12 deficiency." Therefore if you are using cimetidine, it might be worth supplementing vitamin B12.

 

The effects of cimetidine on renal function in patients with renal failure (1980) Larsson R, Bodemar G, Kagedal B, Walan A Acta medica Scandinavica 208 (1-2) pp27-31 explains that cimetidine may cause an increase in creatinine levels. If your cat's creatinine levels rise while using cimetidine, you may find they improve once you stop the medication.

Top ten potential drug interactions on dogs and cats (2008) Trepanier LA Presentation to the World Small Animal Veterinary Association World Congress recommends using famotidine or ranitidine rather than cimetidine.

Pet Place has information about cimetidine (no need to register to read the article, just click on Close at the bottom of the pop-up).

 

Omeprazole (Prilosec, Losec)


Omeprazole belongs to a family of drugs known as proton pump inhibitors (PPIs). These medicines are not acid blockers like famotidine (Pepcid), which block acid after it has been produced but instead work by inhibiting the release of acid into the stomach in the first place. They are therefore often used for the treatment of stomach ulcers, but are also increasingly being used to help CKD cats with excess stomach acid.

 

Antisecretor activity of omeprazole in the conscious gastric fistula cat: comparison with famotidine (1989) Coruzzi G & Bertaccini G Pharmacological Research 21(5) pp499-506 found that omeprazole was "approximately fivefold less potent than famotidine." It found that omeprazole was most effective when the stomach was at the peak of acid production. However, Evaluation of the effect of orally administered acid suppressants on intragastric pH in cats (2015) Parkinson S, Tolbert K, Messenger K, Odunayo A, Brand M, Davidson G, Peters E, Reed A & Papich MG Journal of Veterinary Internal Medicine 29(1) pp104-12 found that omeprazole (in both tablet form, and a reformulated paste form normally used for horses) appeared to be more effective than famotidine. It also found that omeprazole is "generally well tolerated" in cats.

 

The International Renal Interest Society (2013) recommends treating reduced appetite, vomiting or nausea "with a proton pump inhibitor (e.g., omeprazole) and an antiemetic (e.g., maropitant or ondansetron). However, further investigations are needed on the use of these drugs to determine whether they are useful for managing gastrointestinal disturbances in cats with CKD and uraemia."

 

Pet Education has some information about omeprazole.

Veterinary Partner also has some information.

Omeprazole Formulations


Omeprazole is available over the counter in many countries in both tablet (omeprazole) and slow release capsule (omeprazole magnesium) form. Discuss which formulation to use with your vet.

 

Tablets

The tablets usually come in a 20.6mg strength and are supposed to be taken on an empty stomach in the morning, half an hour before eating. They are coated, so are not supposed to be broken up. Plumb's Veterinary Drug Handbook (7th Edition) says "Omeprazole capsules or tablets should not be crushed or chewed." However, Evaluation of the effect of orally administered acid suppressants on intragastric pH in cats (2015) Parkinson S, Tolbert K, Messenger K, Odunayo A, Brand M, Davidson G, Peters E, Reed A & Papich MG Journal of Veterinary Internal Medicine 29(1) pp104-12 found that if you split the tablets into cat-sized doses, "enteric-coated omeprazole tables are effective for acid suppression in spite of the disruption of the enteric coating." Some members of Tanya's Support Group do use the tablets for their cats and find them effective.

 

Walgreens sells 42 tablets in the 20.6mg strength for US$20.99.

 

Capsules

The capsules usually come in a 20.6mg strength and contain omeprazole magnesium. Apparently the magnesium is there to help the capsule dissolve. Magnesium is not ideal for CKD cats, but at least some of the magnesium will be part of the capsule, which you discard.

 

In theory the capsules should not be used for cats, because slow release medicines are not supposed to be opened, but an entire capsule is too big for a cat. Quite a few members of Tanya's CKD Support Group have opened and used capsules successfully for their cats. Plumb's Veterinary Drug Handbook (7th Edition) says "Omeprazole capsules or tablets should not be crushed or chewed. If reducing the dose of the commercially available capsules, the capsule contents should be re-inserted into a gelatin capsule so they cannot be chewed." However, many people do simply mix the capsule contents with their cat's food, see below.

 

If your vet agrees to you using capsules, you will see that each capsule contain beads (microspheres). You should open one of the capsules and count the microspheres. The number varies depending upon the manufacturer. Once you know how many beads your chosen product contains, you can calculate your cat's dose. For example, if your 20mg capsule contains 100 beads, and you want to give your cat 2.5mg, you would give your cat 12-13 beads once a day.

 

If the capsule you try has too many beads to count, try another brand. Walgreens and CVS both produce their own version of omeprazole capsules, but some members of my support group find the CVS brand has tiny beads which seem to carry a lot of static and are therefore very difficult to count. Altosec generic capsules apparently only contain about twenty beads.

 

Walgreens sells 28 20.6mg strength capsules for US$15.99.

Amazon sells 42 20.6mg strength capsules for US$20.95.

 

Compounded

Some people prefer to have omeprazole compounded into capsules or a liquid for their cats. Plumb's Veterinary Drug Handbook (2011) states "Use caution when using compounded omeprazole products; bioequivalence has been an issue with some compounded preparations." Nevertheless, some members of Tanya's Support Group do use compounded omeprazole without problems.

 

Omeprazole Dosage


Pet Place states that "The typical dose administered to animals is 0.25 to 0.5 mg per pound (0.5 to 1.0 mg/kg), every 24 hours or once daily." Thus a 10 lb (4.5kg) cat would receive 2.5 to 5 mg once a day.

 

Omeprazole is excreted via the liver and kidneys, so it may be necessary to adjust the dose downwards in CKD cats. Speak to your vet about a suitable dose for your cat, especially if your cat has more advanced kidney disease.

 

Unlike acid blockers such as famotidine (Pepcid), omeprazole is tasteless. Therefore many people just mix the correct number of beads from the capsule formulation with their cat's food. If you do this, ensure your cat eats the food within 15 minutes. Humans are advised to take omeprazole an hour before food and in the morning, and Plumb's also recommends giving it before meals, ideally in the morning. If you are using the tablet form, I would follow this advice.

 

Some cats respond to omeprazole within a day, but it can take up to a week to take effect. During this period, or if omeprazole alone does not seem to be sufficient to help your cat, your vet may ask you to continue using other treatments. It is acceptable to use omeprazole at the same time as famotidine or ranitidine, as long as your vet approves. Can famotidine and omeprazole be combined on a once-daily basis? Fändriks L, Lönroth H, Pettersson A & Vakil N Scandinavian Journal of Gastroenterology 42(6) pp689-94 found that doing so was safe in healthy humans, and some members of my support group do the same for their cats.

 

The main disadvantage with omeprazole is that in humans, it is used for 14 days only and then not used again for four months. Plumb's Veterinary Drug Handbook mentions that it is thought to be safe to use omeprazole in dogs for at least four weeks. I have been unable to find a recommendation for length of treatment in cats, though I do know of some people who have used it on an ongoing basis. Be guided by your vet as to the best course of action for your cat.

 

Omeprazole Side Effects and Interactions


According to Plumb's Veterinary Handbook, possible side effects include nausea, vomiting and diarrhoea. Urinary tract infections, proteinuria or central nervous system disturbances may also be seen. Omeprazole may also cause a low white blood cell count (neutrophils), though this is rare.

 

Omeprazole may interact with diazepam (Valium), making its effects last longer.

 

One known problem with proton pump inhibitors is that they may inhibit the absorption of nutrients from food, particularly Vitamin B12 and calcium. It is recommended that omeprazole should only be used in humans for eight weeks. Proton pump inhibitor and histamine H2 receptor antagonist use and vitamin B12 deficiency (2013) Lam JR, Schneider JL, Zhao W & Corley DA Journal of the American Medical Association 310(22) pp2435-2442 found that in humans "gastric acid inhibitor use was significantly associated with the presence of vitamin B12 deficiency." Adverse effects of long-term proton pump inhibitor therapy (2011) Sheen E & Triadafilopoulos G Digestive Diseases & Sciences 56(4) pp931-50 mentions that long term use in humans is becoming increasingly common and reviews the possible adverse effects of long term use. The study concluded that the benefits of longer term treatment outweigh the risks for most patients, but that elderly or chronically ill patients "theoretically could be at increased risk from long-term therapy." Therefore if you use it for any length of time, ask your vet if you should start or increase a vitamin B12 supplement.

 

Plumb's Veterinary Drug Handbook mentions that it is thought to be safe to use omeprazole in dogs for at least four weeks. I have been unable to find a recommendation for length of treatment in cats, though I do know of some people who have used it on an ongoing basis. Be guided by your vet as to the best course of action for your cat.

 

If omeprazole is stopped, there may be a rebound effect, i.e. there may be an increase in stomach acid production that is higher than that before the treatment was begun. This can last a couple of weeks. Web MD talks more about this.

 

An unexpected effect of proton pump inhibitors: elevation of the cardiovascular risk factor ADMA (2013) Ghebremariam YT, LePendu P, Lee JC, Erlanson DA, Slaviero A, Shah NH, Leiper J & Cooke JP Circulation 128(8) pp845-53 found that proton pump inhibitors may increase the risk of major adverse cardiovascular events. However, in a later study, Proton pump inhibitors and vascular function: a prospective cross-over pilot study (2015) Vascular Medicine 2. pii: 1358863X14568444. [Epub ahead of print] found that "PPI use [Prevacid] did not significantly influence vascular endothelial function. Larger, long-term and blinded trials are needed to mechanistically explain the correlation between PPI use and adverse clinical outcomes, which has recently been reported in retrospective cohort studies." I do not know whether the same risks might exist with cats, but I would double check with your vet before using omeprazole in a cat with heart problems.

 


Other Treatments                                                                                                  Back to Page Index


If the natural treatments above don't work, and your cat does not respond too well to acid blockers such as famotidine, or perhaps shows some improvement but still vomits fairly frequently, you may need to consider trying one of these other medications. These medications primarily treat nausea and/or vomiting but they work in different ways, so discuss with your vet whether one of them might be suitable for your cat.

 

Treating feline pancreatitis (2009) Robertson J DX Consult 2(1) offers a brief overview of these treatments.

Pharmacologic control of vomiting (2009) Tams TR CVC in Kansas City Proceedings discusses the use of these medications and others in cats.

 

Ondansetron (Zofran)


This drug is commonly used to control vomiting in cats with pancreatitis or cancer, but many people find it effective for nausea in CKD cats too. I first heard of somebody using ondansetron for a CKD cat in 2002, but it has not been used routinely in CKD cats until recently, mainly because it was extremely expensive. Since the generic version became available in the USA, however, it is becoming quite popular for use in CKD cats. Trade names include Zofran in the USA, Setronon in Europe and Emeset in the UK.

 

Ondansetron works in a different way to metoclopramide below (it selectively inhibits serotonin 5HT3 receptors), so it does not lower the seizure threshold as metoclopramide does.

 

Some people use maropitant (Cerenia) for vomiting, but since you are not supposed to use maropitant for more than five days in a row, they use ondansetron on the other days.

 

The Merck Veterinary Manual has some brief information about ondansetron.

 

Some people use another drug in this family, dolasetron (Anzemet), which only needs to be given once a day, but dolasetron seems to be more commonly used at this time for cats with pancreatitis. Plumb's Veterinary Drug Handbook mentions that dolasetron should not be given to patients with certain types of heart problem, and should be used with caution in cats with low potassium levels. Pharmacologic control of vomiting (2009) Tams TR CVC in Kansas City Proceedings has some information about dolasetron.

 

Ondansetron Formulations


 

Ondansetron Pills

Ondansetron comes in 4mg pills, and a commonly used dose is 1 mg each day, so one pill contains four doses. The pills are tiny, so can be hard to cut into quarters.

 

You can be charged as much as US$6 for a single pill, so you need to shop around, because it is possible to buy the generic pills much more cheaply. Costco apparently sell 60 4mg tablets for around US$23. This may work out even cheaper with a pet medication card (see Obtaining Supplies Cheaply). Many UK chemists can supply ondansetron with a prescription from your vet. It is usually much cheaper to buy more pills at one time.

 

Good RX allows you to search for discounted medications in your area in the USA. As an example, I found 30 ondansetron 4mg for less than US$14 in NYC.

Health Warehouse sells 30 ondansetron 4mg tablets for US$26.10 including shipping, but the first order can take up to two weeks.

Thriving Pets sells ondansetron for US$1 per 4mg pill, or 80 cents each if you buy thirty. 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$100. Shipping is free for orders over US$100 after the discount.

Pharmplex Direct in the UK sells ondansetron for £6.25 for 30 plus shipping (total cost is a little under £10). A prescription is required.

 

Ondansetron Injectable

There is also an injectable form of ondansetron. Thriving Pets sells 2mg/ml in a 20ml vial (forty doses for many cats) for US$19.95. If you enter the word "tanya" (without the ") in the promotional code box, you will receive a 10% discount on orders over US$100. Shipping is free for orders over US$100 after the discount.

 

Unfortunately injectable ondansetron stings a lot, but it may be a good choice for a cat who is struggling to keep anything down, and it does work quickly - you should see results within a couple of hours. It can help if you give some of the fluids before you add the ondansetron.

 

Ondansetron Dosages


Ondansetron comes in 4mg pills, and a commonly used dose on Tanya's Support Group is 1 mg each day, so one pill contains four doses.

 

This seems to work well for many CKD cats; however, Pet Place mentions that the usual dose for cats is 0.11mg per pound bodyweight every 8-12 hours, i.e. 1.1mg for a 10 lb (4.5kg) cat given 2-3 times a day. Plumb's Veterinary Drug Handbook mentions an empiric dose of 0.5mg per kg bodyweight twice daily, so a 10 lb (4.5kg) cat would be given 2.25mg twice a day. 

 

Oral, subcutaneous and intravenous pharmacokinetics of ondansetron in healthy cats (2014) Quimby JM, Lake RC, Hansen RJ, Lunghofer PJ & Gustafson DL Journal of Veterinary Pharmacology and Therapeutics 37(4)  pp348–353 found that subcutaneous administration was more effective then oral dosing. It also states "twice daily administration at 0.5 mg/kg is likely inadequate to maintain serum concentrations within the therapeutic range; higher or more frequent doses may be needed." However, it further states that "the postulated therapeutic range - extrapolated from a previously published pharmacodynamic study - may not be accurate particularly if applied to repeated administration for chronic disease states." The study says that "A placebocontrolled clinical trial will be necessary to confirm which dose would be clinically effective for palliation of chronic nausea and vomiting in cats."

 

Obviously there are quite sizable differences between these doses. The above study found "Poor bioavailability should be taken into account when determining a route of administration for a patient as individual oral bioavailability ranged from 11 to 50% in the cats used in this study." For acute vomiting, such as in a cat with pancreatitis, higher and/or more frequent dosing may indeed be necessary. For chronic nausea in CKD cats, however, many people find the lower dose is fine, though they may need to give ondansetron twice or even three times daily.  I would start with the lower dose of 1 mg each day, and if you find this is not enough, speak to your vet about increasing the dose or frequency.

 

Ondansetron Interactions and Side Effects


Possible side effects include constipation, low blood pressure and sleepiness. Humans have reported bad headaches. Drugs has more information about possible side effects.

 

Ondansetron may also cause heart arrhythmias. In September 2011 The US Food & Drug Administration reported that "Ondansetron may increase the risk of developing abnormal changes in the electrical activity of the heart, which can result in a potentially fatal abnormal heart rhythm." 

 

Drugs says that using ondansetron and mirtazapine (used in CKD cats as an appetite stimulant) together may increase the risk of serotonin syndrome.

 

Ondansetron inhibits the analgesic effects of tramadol: a possible 5-HT3 spinal receptor involvement in acute pain in humans (2002) Arcioni R, della Rocca M, Romano S, Romano R, Pietropaoli P & Gasparetto A Anesthesia and Analgesia 94(6) pp1553-7 reports that ondansetron may reduce the painkilling effects of tramadol by up to 50% in humans. It is not known if the same applies to cats.

 

Maropitant (Cerenia)


Maropitant (Cerenia) is a relatively new treatment from Pfizer which works by inhibiting neurokinin (NK) inhibitors. In other words, it works by blocking the stimulation of the part of the brain that instigates vomiting.

 

The injectable form is approved for the treatment of vomiting and nausea in cats (and dogs) in Europe and the USA. In Europe, injectable maropitant is also approved for travel sickness in cats. Treatment for visceral pain with the new NNK-1 receptor antagonist maropitant in cats (2011) Boscan P, Monnet E, Twedt D & Nyiom S, found that maropitant may also be an effective painkiller, so it may be a good choice for a vomiting cat with pancreatitis.

 

Maropitant only needs to be given once a day and does appear to be very effective for some cats, usually taking effect within an hour.  Chronic use of maropitant for the management of vomiting and inappetance in cats with chronic kidney disease: a blinded placebo-controlled clinical trial (2014) Quimby JM, Brock WT, Moses K, Bolotin D, Patricelli K Journal of  Feline Medicine & Surgery 21. pii: 1098612X14555441 found that there was a significant reduction in vomiting in CKD cats given maropitant; however it did not seem to improve appetite.

 

Some people find maropitant works better for their cats than ondansetron, so if you are not finding ondansetron to be as effective as you hoped, I would try maropitant instead.

Maropitant Formulations


Maropitant is available in either injectable or pill form. Both the injectable and the pill form are intended to prevent vomiting, but the injectable form is also designed to treat acute vomiting. Only the injectable form is approved for use in cats, but the pill form is used off label. The injectable form seems to sting some cats, and the oral form seems to taste horrible.

 

Maropitant Tablets

Maropitant comes in 16mg-sized tablets so most people use these and break them into suitable sizes for their cat.

 

Drs Foster & Smith sell four 16mg tablets for US$8.99.

 

Maropitant Injectable

Unfortunately there is no generic injectable form of maropitant, and injectable Cerenia costs around US$150 or more per vial. A typical dose would be 4mg daily (0.4 ml), so a 20 ml vial provides 50 doses costing around $3.20 each.

 

Injectable maropitant also stings very badly. Keeping it in the fridge may help with this. Once opened, the vial should be stored in the fridge anyway. Drugs states that it will keep for 90 days in the fridge, but that the stopper should not be punctured more than 25 times.

 

Thriving Pets sells 10 mg/ml in a 20ml vial for US$159.95. This provides around 50 doses (depending upon the size of the cat) costing US$3.20 each. 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$100. Shipping is free for orders over US$100 after the discount.

 

You may be able to get maropitant more cheaply from a compounding pharmacy.

 

Maropitant Dosages


 

Oral

For the oral form, a commonly recommended dose is 1mg per kg (2.2lbs) of body weight. Safety, pharmacokinetics and use of the novel NK-1 receptor antagonist maropitant (Cerenia) for the prevention of emesis and motion sickness in cats (2008) Hickman MA, Cox SR, Mahabir S, Miskell C, Lin J, Bunger A, McCall RB Journal of Veterinary Pharmacology and Therapeutics 31(3) pp220-9 states "The results indicate that maropitant is an effective, well tolerated and safe anti-emetic in cats at a dose of 1.0 mg/kg." A 10 lb cat (4.5 kg) cat would therefore receive 4.5 mg. Most people seem to buy the 16mg size and divide it as appropriate (into quarters for a 10 lb cat).

 

The pills should not be given in Pill Pockets or mixed with food as this may stop them being properly absorbed in the cat's body, but some people do give them this way. Many people place the medication in a gelcap in order to hide the taste.

 

Injectable

For the injectable form, the European Medicines Agency states that it  is given "once daily under the skin (1ml per 10 kg bodyweight) for up to five days." Since the injectable form is 10mg/ml strength, this means that the standard dosage is 1mg per kg bodyweight, the same as the oral dosage Therefore a  10 lb (4.5kg) cat would receive 4.5mg a day, or 0.45 ml.

 

Plumb's Veterinary Drug Handbook states that 0.5 to 1 mg per kg bodyweight can be given for up to five days. This would mean that a 10 lb (4.5kg) cat would receive 2.25-5.00 mg a day, or 0.225-0..5ml a day.

 

Maropitant Breaks


The manufacturer recommends that maropitant should only be given short term to dogs, for a maximum of five days at a time. Off label use of drugs in veterinary medicine (2013) Coates J explains that using maropitant for longer can reduce dopamine levels in the central nervous system and lead to tremors. Some people have used it in their cats for a few days, taken a break, then used it again. Plumb's Veterinary Drug Handbook mentions that the medication should be stopped for at least 48 hours in these circumstances.

 

In Safety, pharmacokinetics and use of the novel NK-1 receptor antagonist maropitant (Cerenia) for the prevention of emesis and motion sickness in cats (2008) Hickman MA, Cox SR, Mahabir S, Miskell C, Lin J, Bunger A, McCall RB Journal of Veterinary Pharmacology and Therapeutics 31(3) pp220-9, maropitant was used for fifteen days without a break in cats with no apparent problems, though one cat did have minor tremors while asleep. I know that after learning about this study, some people have given their cats maropitant for longer than five days and not seen any adverse effects. In Chronic use of maropitant for the management of vomiting and inappetance in cats with chronic kidney disease: a blinded placebo-controlled clinical trial (2014) Quimby JM, Brock WT, Moses K, Bolotin D, Patricelli K Journal of  Feline Medicine & Surgery 21. pii: 1098612X14555441, 4 mg of maropitant was given orally to cats once every day for 14 days without a break. Colorado State University College of Veterinary Medicine, which led this study, has stated that they are prepared to give their patients maropitant on a daily basis without a break. Be guided by your vet on the best approach for your cat, and monitor your cat closely for tremors or shaking.

 

Maropitant Side Effects and Interactions


Possible side effects include vomiting, lethargy, diarrhoea, anorexia, twitching and drooling.  Maropitant should not be used if there is any gastrointestinal obstruction, and should be used with caution if liver or heart problems are present (it may increase the risk of arrhythmias). Drugs has more information.

 

The European Medicines Agency says (clause 4.8 on page 9) that "Cerenia should not be used concomitantly with Ca-channel antagonists as maropitant has affinity to Ca-channels." The University of Zürich Institute for Veterinary Pharmacology and Toxicology also mentions this (in German). In principle this means that maropitant should not be used with calcium channel blockers such as amlodipine (Norvasc or Istin, commonly used to treat high blood pressure in CKD cats).  'Concomitantly' has a rather vague medical meaning in that it means during the same time period, but in this context I don't know exactly what time period the EMA is referring to, i.e. do they mean at the same time or on the same day? Both of these medications tend to be given once daily, so they have a relatively long effect. I suspect that giving them both on the same day but 12 hours apart (i.e. one in the morning and one in the evening) would probably be acceptable, but check with your vet.

 

The European Medicines Agency also warns that urgent medical attention should be sought if maropitant gets in the eyes. The University of Zürich Institute for Veterinary Pharmacology and Toxicology also mentions the issue of eye irritation.

 

Pfizer product information sheet (tablets) mentions that maropitant should only be given for five days. It also states that maropitant may interact with phenobarbital, used to control epilepsy, and NSAIDs.

Pfizer product information sheet (injectable) also mentions this.

Veterinary Partner has some information about the use of maropitant in dogs, which explains more about its mechanism.

Drs Foster and Smith have an information sheet about the use of maropitant in dogs.

 

Metoclopramide (Reglan or Emeprid)


Metoclopramide is a prescription only medication which works by regulating stomach contractions. This means it can help with nausea caused by a lack of motility in the stomach. Pet Place has some information about gastric motility problems in cats (you don't need to register to read the article, just click on Close at the bottom of the pop-up window).

 

Since metoclopramide can cross the blood/brain barrier, it also acts on the brain to control feelings of nausea.

 

When I first set up this website in 2000, quite a few people used metoclopramide for their cats if the histamine H2 antagonists were not sufficient. I do not recall there being too many problems with the medication over subsequent years. On 26 February 2009, the US Food and Drug Administration warned against the "chronic use of these products [metoclopramide-containing drugs] to treat gastrointestinal disorders." This is because products containing metoclopramide have been linked to a condition called tardive dyskinesia, i.e. involuntary and repetitive movements of the body, which may continue even after the treatment is stopped. One such movement mentioned by the FDA is lipsmacking (although it should be noted that lipsmacking in CKD cats is normally caused by excess stomach acid or nausea, anaemia or dehydration). The FDA therefore recommends that products containing metoclopramide should not be used for longer than three months.

 

In July 2013 the European Medicines Agency went further and announced that metoclopramide should only be used short term (up to five days) and that it should only be used in adults "for the prevention and treatment of nausea and vomiting such as that associated with chemotherapy, radiotherapy, surgery and in the management of migraine." In addition, it recommended that dosages should be lowered.

 

Obviously these warnings apply to humans, but since there are now other treatments available as outlined above which carry fewer risks, I would only use metoclopramide as a last resort. Be sure to discuss these warnings with  your vet before using metoclopramide.

 

Metoclopramide Dosages


Metoclopramide comes in 10 and 5mg tablets or a liquid. Injectable metoclopramide is also available as 5mg/ml in 2 ml or 10 ml vials. It must be given 20-30 minutes before eating.

A typical dose would be 0.1 to 0.2 mg per pound (0.2 to 0.5 mg per kg) every six to eight hours, so a 10lb (4.5kg) cat would get 1 mg to 2 mg at a time. Plumb's Veterinary Drug Handbook mentions that dosages may need to be reduced in animals with kidney disease, so be guided by your vet.

 

Metoclopramide Side Effects and Interactions


Please see the important warning above.

 

Metoclopramide may have various side effects, including constipation, hyperactivity and agitation or drowsiness; very occasionally, twitching may be seen.

 

Metoclopramide also lowers the seizure threshold, so should not be given to cats prone to seizures. Drugs mentions that it may increase the risk of bronchospasm in asthmatics, and intravenous metoclopramide may worsen hypertension (high blood pressure).

 

I used to recommend giving metoclopramide at least two hours apart from famotidine (Pepcid AC) or ranitidine (Zantac 75) because, according to Plumb's Veterinary Drug Handbook, the metoclopramide could bind with these other medications and reduce their effectiveness. However, the most recent edition of Plumb's does not mention this interaction, so it appears that you do not need to separate metoclopramide from these other medications after all.

 

Using metoclopramide as well as mirtazapine (appetite stimulant) increases the risk of serotonin syndrome. You can read more about this and what to watch for here.

 

Veterinary Partner has more information on metoclopramide.

Pet Place also has some information (no need to register to read the article, just click on Close at the bottom of the pop-up).

Drs Foster and Smith have some information about possible side effects. They also mention that metoclopramide is similar to PABA, the sunscreen component, so people who are allergic to PABA should not touch metoclopramide.

 


Cautions                                                                                                                                           Back to Page Index


The following are not recommended for CKD cats.

Pepto-Bismol


Please do not use Pepto-Bismol. It contains a type of salicylate, similar to what is found in aspirin, and cats are not able to metabolise this easily, so it may be fatal even in small doses.

 

Pet Place warns against using Pepto-Bismol in cats.

Pet Education has more information on Pepto-Bismol.

Antacids


Some vets recommend the use of antacids, such as Tums or Mylanta. Some products in this family do actually work well in CKD cats as phosphorus binders, but they are not usually strong enough to help control excess stomach acid, plus using products containing magnesium is not usually recommended for CKD cats, who tend to have high levels of magnesium generally. 

              

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This page last updated: 25 May 2015

Links on this page last checked: 25 May 2015

   

*****

 

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.

 

*****

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