H2 Blocker Side Effects
While most people tolerate H2 blockers well, side effects may occur during treatment with these medicines. Some common H2 blocker side effects include abdominal pain (or stomach pain), constipation, and diarrhea. There are also a number of more serious side effects that may occur, including hallucinations, unusual rash, and angioedema (life-threatening swelling of the throat and mouth). Notify your healthcare provider immediately if you experience any of these more serious side effects.
An Overview of H2 Blocker Side EffectsAs with any type of medicine, there are possible side effects with H2 blockers. However, not everyone who takes an H2 blocker will experience side effects. In fact, most people tolerate H2 blockers well. When side effects do occur, in most cases they are minor and either require no treatment or can easily be treated by you or your healthcare provider. There are also several factors that seem to affect the chances of side effects, including:
- The dosage and type of H2 blocker
- Other medical conditions you may have
- Other medicines being taken at the same time.
(This article covers many, but not all, possible side effects of H2 blockers. Your healthcare provider can discuss a more complete list of H2 blocker side effects with you.)
Common Side Effects of H2 BlockersEach H2 blocker has been studied thoroughly in clinical trials. In these studies, the side effects that occur in a group of people taking the drug are documented and are then compared to side effects that occur in another group of people 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, some of the most common side effects of H2 blockers included:
- Abdominal pain (or stomach pain)
- Breast enlargement in men (gynecomastia), especially with cimetidine (Tagamet®)
- An irritated or runny nose
- Nausea or vomiting
- A sore throat