NCIt definition : The hydrobromide salt form of homatropine, a synthetic tertiary amine alkaloid with
antimuscarinic properties. Homatropine, a competitive inhibitor of acetylcholine at
the muscarinic receptor, blocks parasympathetic nerve stimulation. When applied topically
to the eye, dilation of the pupil (mydriasis) and paralysis of accommodation (cycloplegia)
result from the local anticholinergic effects on the ciliary muscle and iris.;