Tagamet was the first of a new class of ulcer drugs, called "H2 antagonists."
It works by suppressing the secretion of stomach acid, so it is also used to treat conditions of abnormal acidity such as serious heartburn as well as helping ulcers clear up rapidly.
Doctors sometimes prescribe Tagamet as maintenance therapy to keep ulcers from coming back.
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, h 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.
Perhaps because Tagamet is so effective at reducing stomach acid concentrations, patients taking this medicine have higher levels of certain microorganisms in their stomachs than would normally survive there.
Scientists do not yet know whether these bacteria have negative long-term consequences.
Regular supplementation with vitamins C and E might in theory provide protection against possible adverse consequences.
People with liver or kidney trouble may not be able to tolerate the usual dose of Tagamet. Ask your doctor to monitor you as you begin this medicine.
Tagamet may be taken with food, especially if it upsets your stomach.
If antacids are needed for relief of ulcer pain, they should generally be taken at a different time.