Tagamet Side Effects

In clinical trials of Tagamet, side effects most commonly reported with the drug included breast enlargement in men and headaches. Other common side effects of the drug include diarrhea, dizziness, and drowsiness. Some side effects of Tagamet may be serious and require immediate medical attention, such as an irregular heart rhythm or signs of an allergic reaction (such as swelling of the mouth or throat).

Tagamet Drug Information

Tagamet Side Effects: An Introduction

As with any medicine, there are possible side effects with Tagamet^® (cimetidine); however, not everyone who takes this drug will experience side effects. In fact, most people tolerate Tagamet well. When people do develop Tagamet side effects, in most cases they are minor, meaning they require no treatment or are easily treated by you or your healthcare provider.

(This article covers many, but not all, of the possible side effects with Tagamet. Your healthcare provider can discuss a more complete list of Tagamet side effects with you.)

Common Tagamet Side Effects

Tagamet has been studied thoroughly in clinical trials in which a group of people taking the drug have side effects documented and compared to another group not taking the medicine.

This way, it is possible to see what side effects occur, how often they appear, and how they compare to the group not taking the medicine.

In these studies, the most common side effects of Tagamet included:

Breast enlargement in men (gynecomastia) -- in up to 4 percent of people (see Cimetidine and Gynecomastia)
Headaches -- up to 3.5 percent
Diarrhea -- up to 1 percent
Dizziness -- up to 1 percent
Drowsiness -- up to 1 percent.

(Tagamet Side Effects Continued: Page 2)