Homatropine

Homatropine is a tropane alkaloid derivative. Homatropine competitively binds to and inhibits muscarinic acetylcholine receptors, especially M₃ receptors. In the eye, it inhibits the sphincter pupillae muscle, causing mydriasis, and inhibits contraction of the ciliary muscle, producing cycloplegia. In the gastrointestinal tract and other visceral organs, homatropine suppresses parasympathetic activity, leading to smooth muscle relaxation and reduced intestinal motility and secretion.