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Drug Details

  • Drug Name: Cimetidine
  • Common Name: Tagamet®
  • Drug Type: H2 blocker
  • Used For: Stomach ulcers
  • Species: Dogs, Cats
  • Administered: Oral liquid, Tablets
  • How Dispensed: Over the counter
  • FDA Approved: No

General Description

Cimetidine is a histamine (H2) blocker that is used to prevent and treat stomach and intestinal ulcers. It is often prescribed in the cases of parvovirus, irritable bowel syndrome, megaesophagous, and acid reflux to soothe inflammation and assist in healing.


Give this medication without food, as food will decrease it’s effectiveness.


How It Works


Histamine is a key component in the allergic reaction, causing inflammation and swelling. It can often cause stomach cramping and diarrhea as well. By inhibiting the H2 receptor, a receptor for histamine, Cimetidine reduces the output of stomach acid. This reduces the pH of the digestive system, giving the ulcer in the stomach time and a more favorable environment to rest and heal.


Storage Information


Store in a tight container at room temperature protected from light and heat.


Missed Dose?


Give the dose as soon as possible. If it is almost time for the next dose, skip the missed dose, and continue with the regular schedule. Do not give your pet two doses at once.


Side Effects and Drug Reactions


Cimetidine is safe to use in older pets with liver or kidney disease or blood abnormalities. Side effects are very rare.

Cimetidine may react with these drugs, as they absorb best in the presence of stomach acid:


  • Ketoconazole
  • Itraconazole
  • Antacids
  • Metoclopramide
  • Sucralfate
  • Digoxin


It is best to give these medications at least two hours prior or following the use of Cimetidine.


Cimetidine may also react with Azathioprine and other bone marrow suppressing drugs. Please consult your veterinarian before giving these or any other drug or herbal supplement to your pet while on Cimetidine.





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