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 include diarrhea, dizziness, and drowsiness. Some reactions to Tagamet may be serious and require immediate medical attention, such as an irregular heart rhythm or swelling of the mouth or throat.
As with any medicine, side effects with are possible with Tagamet® (cimetidine); however, not everyone who takes this drug will experience problems. In fact, most people tolerate it well. If side effects do occur, in most cases, they are minor, meaning they require no treatment or are treated easily by you or your healthcare provider.
(This article covers many, but not all, of the possible Tagamet side effects. Your healthcare provider can discuss a more complete list with you.)
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.