By Rania Gollakner, BS, DVM, MPH

What is ranitidine? 

Ranitidine (brand name Zantac®) is an H2 receptor antagonist (a type of acid reducer) used to treat and prevent ulcers occurring in the stomach and small intestine in dogs and cats. It is also used to treat stress-related, kidney disease-related, or drug-induced erosive gastritis, esophagitis, and esophageal reflux. Ranitidine may also be used to stimulate contractions of the stomach and to stimulate bowel activity in cats and rabbits. It may also be used in rabbits for the treatment of stomach ulcers and in ferrets to treat Helicobacter mustelae. The medication works by reducing the amount of acid secreted in the stomach.

The use of ranitidine in dogs, cats, and other animals is “off-label”. Many drugs are commonly prescribed for off-label use in veterinary medicine. In these instances, follow your veterinarian’s directions and cautions very carefully.

How is ranitidine given?

Ranitidine is available as a tablet, capsule, oral syrup, and in an injectable form. It is available over the counter BUT you should only give it to your pet if your veterinarian has prescribed it.

Ranitidine works best when given by mouth on an empty stomach before the first meal of the day. If your pet vomits after receiving the medication, try giving it with a small amount of food. Follow the dosing instructions provided by your veterinarian. Measure liquid forms carefully. Your veterinarian will administer the injectable form.

Stopping the medication before the therapy is complete may cause the condition to return.

This medication should take effect within one to two hours; however, effects may not be visibly noticeable.

What if I miss giving my pet the medication?

If you miss a dose, do not give it when you remember. Instead, wait and give the next dose at the usual time. Never give your pet two doses at once or give extra doses.

It is very important to give the medication for the length of time your veterinarian has recommended. Do not stop giving the medication to your pet without first speaking with your veterinarian.

Are there any potential side effects?

There are very few reported side effects of ranitidine. If you notice any abnormal signs associated with this medication, contact your veterinarian. If your veterinarian injects ranitidine, pain at the injection site may occur.

This short-acting medication should stop working within 24 hours, although effects can be longer in pets with liver or kidney disease.

Are there any risk factors for this medication?

Ranitidine should not be used in patients that have an allergy to it or other similar drugs, such as famotidine (Pepcid®) or cimetidine (Tagamet®). This medication should be used with caution in pregnant or nursing pets. It should be used cautiously in pets with kidney or liver disease.

This short-acting medication should stop working within 24 hours, although effects can be longer in pets with liver or kidney disease.

Are there any drug interactions I should be aware of?

Ranitidine may interact with other drugs including antacids, certain antifungals, cephalosporins, certain heart medications, and propantheline (Pro-Banthine®). Tell your veterinarian about any medications (including vitamins, supplements, or herbal therapies) that your pet is taking.

Is there any monitoring that needs to be done with this medication?

Monitor to ensure that the medication is working.

How do I store ranitidine?

Ranitidine tablets and capsules should be stored in a tightly sealed, light-resistant container and at room temperature, between 20°C and 25°C (68°F to 77°F). Liquids should be stored as recommended on the label and discarded by the date shown on the bottle. If your veterinarian has made a special formulation, follow the storage instructions provided with the medication.

What should I do in case of an emergency?

Very high doses of ranitidine can cause toxic effects. If you suspect an overdose or an adverse reaction to the medication, call your veterinary office immediately. If they are not available, follow their directions in contacting an emergency facility.

Related Articles