Which H2 antagonist is associated with anti-androgen side effects?

Cimetidine is the H2 antagonist associated with anti-androgen side effects. This medication has a chemical structure that allows it to bind to androgen receptors and inhibit the action of androgens in the body, which can lead to side effects such as gynecomastia, impotence, or decreased libido in some men. These hormonal side effects are particularly relevant when considering the potential impact on patients who may be predisposed to such conditions.

The other H2 antagonists—ranitidine, nizatidine, and famotidine—do not exhibit the same degree of anti-androgen effects and are less likely to cause these hormonal imbalances. Ranitidine, nizatidine, and famotidine have more favorable side effect profiles concerning hormonal activity, which makes cimetidine distinct in this regard. Understanding these differences is crucial for safe prescribing and management of patient symptoms related to H2 antagonist therapy.