PetMD Editorial
Written by:
PetMD Editorial
Published: July 18, 2014

Drug Info

  • Common Name: Pepcid
  • Generics: Yes
  • Drug Type: H2 Receptor Antagonist
  • Used For: Decrease Stomach Acid
  • Species: Dogs, Cats
  • Administered: Oral
  • How Dispensed: Prescription & Non Prescription
  • Available Forms: 10mg (Non-RX), 20mg (RX only)
  • FDA Approved: Yes


Famotidine is used to help reduce the amount of stomach acid produced. It aids in the treatment of stomach ulcers that are present and helps prevent ulcer formation. Famotidine can also be used to treat gastritis, esophagitis, and gastric or esophageal reflux as well as prevent stomach or duodenal ulcers in animals with kidney failure.

Dosage and Administration

Famotidine should be given according to your veterinarian’s instructions. When dispensing the tablet, do not give Famotidine with food as it will decrease the effectiveness.

Missed Dose?

If a dose of Famotidine is missed, signs may recur but give the dose as soon as possible. If it is almost time for the next dose, skip the missed dose and continue your regular schedule. Do not give two doses at one time.

Possible Side Effects

Side effects from Famotidine are rare but could include:

  • Loss of appetite
  • Drowsiness

Please contact your veterinarian immediately if you notice any side effects.


Do not use in animals that are allergic to famotidine. If allergic reaction occurs you may notice facial swelling, hive, scratching, sudden onset of diarrhea, vomiting, shock, seizures, pale gums, cold limbs, or coma. If any of these symptoms are present please contact your veterinarian immediately.

Use caution when giving Famotidine to pregnant animals, as it may affect weight gain as well as older animals or those with heart, liver or kidney disease.


Famotidine should be stored between 68-77oF (20-25°C). Store out of children’s reach.

Drug Interactions

When using Famotidine, please consult your veterinarian with any other medications you are currently giving your pet, including supplements, as interaction could occur.  Antacids, Metoclopramide, Sucralfate, Digoxin, or Ketoconazole may cause interactions with Famotidine. Give Famotidine two hours before or two hours after other medications.

Giving Famotidine with other bone marrow suppressing drugs, such as Azathioprine, may decrease white blood cell count.

Signs of Toxicity/Overdose

Overdose of Famotidine is rare but symptoms of an overdose may include:

  • Vomiting
  • Restlessness
  • Redness of the mouth and ears
  • Rapid heart rate
  • Collapse

If you suspect or know you pet has had an overdose, it could be fatal so please contact your veterinarian, an emergency vet clinic, or the Pet Poison Helpline at (855) 213-6680 immediately.

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