People's Pharmacy

Cimetidine

Other Brand Names: Tagamet

Revised:4/1/2000

Table of Contents

Side Effects and Interactions

Side effects associated with Tagamet are not common. However, headache, drowsiness, dizziness and diarrhea have been reported.

Older patients may experience mental confusion or even hallucinations.

Other adverse reactions that have been reported include impotence, breast enlargement in men, rash, hair loss, changes in heart rhythm, liver problems and blood alterations. Report any symptoms to your physician promptly.

Tagamet can interact with many other drugs. The blood thinner Coumadin may become far more potent in the presence of Tagamet and can lead to dangerous bleeding.

Tell your doctor right away if you experience any unusual bruising, bleeding, reddish urine or blackened stools.

Tagamet may also increase blood levels of the asthma drug theophylline, possibly to dangerous levels.

Other prescription drugs that may be more dangerous with Tagamet include anticonvulsants like Dilantin or Tegretol, the anti-fungal medicine Nizoral and certain drugs prescribed to control irregular heart rhythms (moricizine, procainamide, quinidine).

Certain others don't mix well either, such as anti-anxiety agents like Valium, some beta blocker blood pressure drugs, antidepressants like Pamelor, and oral diabetes medicines.

Nonprescription drugs that interact with Tagamet include antacids, alcohol, caffeine and cigarettes.

Caffeine may have more impact on people taking this medicine, while cigarette smoking may tend to counteract its anti-ulcer benefits.

People taking acid-suppressing drugs such as Tagamet should not take enteric-coated peppermint oil. The enteric coating is designed to keep the oil from being absorbed until it reaches the more alkaline lower intestine. But when there is very little stomach acid, the enteric coating may dissolve prematurely, releasing the oil into the stomach.

Check with your pharmacist and physician before taking any other medication or herb in combination with Tagamet.