Master Cimetidine and Famotidine (H2 Receptor Blockers) with Picmonic for Medicine

H2 receptors stimulate the secretion of gastric acid. H2 receptor antagonists block this action and result in decreased production of gastric acid.

H2 receptor antagonists bind and suppress the secretion of acid by parietal cells. Additionally, the activity of acetylcholine and gastrin, the two major preceptors to the production of acid are also reduced.

H2 receptor antagonists can elicit the development of pneumonia by increasing the pH of the stomach, making it more basic. When the pH is increased, bacteria are able to colonize the stomach and may migrate up to the respiratory tract.

Cimetidine can produce antiandrogenic effects by binding to the androgen receptors and blocking the function of androgen receptors. This blockade can cause decreased libido, impotence, and gynecomastia. These effects are reversible once the drug is stopped.

Cimetidine can result in CNS changes, therefore it should be used with caution, especially with elderly patients who have pre-existing liver or kidney dysfunction. Side effects involving the CNS are more prominent in this population. These side effects include hallucinations, confusion, and CNS depression or excitation.