Famotidine for Cats - Uses, Dosage and Side Effects

Famotidine is a medication which is a type of H2 receptor antagonists. H2 is a receptor for histamine, which is the most prominent paracrine stimulant of stomach acids. Histamine is released only after the action of gastrin, a peptide hormone released by the stomach, duodenum and pancreas. If this receptor is blocked by famotidine, histamine cannot bind, so the secretion of stomach acid is limited.

Gastric acid is necessary for digestion in a healthy cat. However, too much gastric acid secretion can either cause health problems or exacerbate existing ones. Hypersecretory disorders caused by excess production of gastric acid include inflammation of the esophagus (esophagitis in cats), inflammation of the gastric mucosa (gastritis in cats), gastrointestinal ulcers creating a more alkaline environment and gastroesophageal reflux. Famotidine also helps to facilitate gastrointestinal transit and acts as a protector for the mucosa of the digestive tract.

When famotidine is metabolized, it passes through the cerebrospinal fluid and breast milk of lactating cats. The effect of inhibition of gastric acids has a limited effect which lasts a period of hours. Daily doses are required for the treatment of these disorders in cats. The metabolism of famotidine is hepatic and most of it is eliminated by the kidneys.

As we have explained the mechanism of famotidine's action above, we can understand this active ingredient is useful for those cats that have hypersecretion problems or problems related to stomach acid. These digestive problems in cats include:

• Gastric or gastrointestinal ulcers
• Esophagitis or inflammation of the esophagus
• Gastroesophageal reflux
• Gastritis or uremic gastric inflammation (due to chronic kidney disease or stress)
• Gastric acid hypersecretory disorders

In addition to treating these problems, famotidine has the potential to increase the movement of the gastrointestinal tract, known as peristalsis. It does so by blocking the enzyme acetylcholinesterase, in turn leading to an increase in acetylcholine that induces the movements of the food bolus through the gastrointestinal tract. This is useful for feline problems such as constipation. Famotidine can also be used to protect the gastrointestinal mucosa after continued use of nonsteroidal anti-inflammatory drugs (NSAIDs) which induce mucosal damage.

Finally, this drug can also be used to treat nausea related to the use of some medications, kidney disease, diabetes, pancreatitis, cancer, irritable bowel syndrome and poisoning. A nauseated cat exhibits signs such as anorexia, lip smacking, food refusal, drooling, constant gulping and vomiting.

Learn more with our article on why cats vomit yellow substances.

In cats, famotidine is used at a dose of 0.5 to 1.1 milligrams per kilogram of body weight. It is taken orally every 12 to 24 hours. Generally, we find famotidine tablets of 10, 20 or 40 mg, although we can also find it in powder format for oral suspension at a concentration of 8 mg per ml.

The dosage of famotidine for cats will depend on whether it is in oral suspension or in tablets, as well as the weight of the cat and the specific formulation of each medication. Your veterinarian will provide the exact the amount you need to obtain the required dose of famotidine to make treatment effective. It is very important not to self-medicate the animal or alter the dose specified by the veterinarian without their prior consent.

Learn about another type of gastric acid inhibitor with our article on omeprazole for cats.

The use of famotidine is contraindicated in the following situations:

• Geriatric or very sick cats
• Cats with liver disease
• Cats with kidney disease
• Cats with hypersensitivity to H2 antagonists
• Cats with hypersensitivity to any of the drug's excipients
• Term-pregnant cats
• Lactating cats

It is important not to give famotidine to lactating or pregnant cats. In the former, it can pass into the milk and block the production of gastric acid in kittens, inhibit the metabolism of other drugs and produce nervous signs by stimulating the central nervous system.

As an inhibitor of histamine H2 receptors, the use of famotidine is contraindicated when cats are also being treated with other drugs with which they have interactions. These are mainly certain antibiotics such as cephalosporins because famotidine can alter their pharmacokinetics.

Iron salts, oral antacids such as magnesium or aluminum hydroxide, as well as antifungals such as ketoconazole or itraconazole are contraindicated as they require an acidic environment for absorption. Since famotidine causes the digestive environment to be more alkaline, it limites the absorption of these antifungals. It is also important to note that the use of famotidine can cause an increase in the liver enzyme alanine aminotransferase (ALT).

Learn more about another type of H2 receptor inhibitor with our article on ranitidine for cats.

Although they are relatively infrequent, famotidine can cause some side effects in cats. Side effects of famotidine include:

• Decreased appetite
• Anorexia
• Vomiting
• Diarrhea
• Dry mouth
• Restlessness
• Altered heart rhythm
• Rapid breathing (tachypnea )
• Collapse
• Muscle tremors
• Hypersecretion of gastric acid after cessation of treatment
• Accumulation of the active ingredient in cats with liver or kidney disease

We insist that only a veterinary professional must indicates the use of this drug. They will explain the dosage and frequency to avoid the above side effects. Misuse of medication in cats can lead to serious consequences.

This article is purely informative. AnimalWised does not have the authority to prescribe any veterinary treatment or create a diagnosis. We invite you to take your pet to the veterinarian if they are suffering from any condition or pain.

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