What is a common side effect associated with pilocarpine?

Pilocarpine is a cholinergic agent that stimulates the parasympathetic nervous system, leading to increased secretions and activity in various bodily systems. One of the common side effects associated with pilocarpine is diaphoresis, or excessive sweating. This occurs because pilocarpine enhances the activity of acetylcholine at muscarinic receptors, which governs sweat gland function.

Increased sweating can be particularly notable in patients taking pilocarpine for conditions like dry mouth (xerostomia) or for treating glaucoma, as the increased cholinergic activity can affect multiple organ systems. This effect is a direct manifestation of activating the parasympathetic nervous system, which is also responsible for other secretory processes in the body.

While headache, drowsiness, and diarrhea are possible side effects of various medications, they are generally not as closely associated with pilocarpine specifically as diaphoresis is. Understanding the mechanism of action of cholinergic agents like pilocarpine helps clarify why diaphoresis is a prominent side effect.