Homatropine
Homatropine is an anticholinergic drug that acts as an antagonist at muscarinic acetylcholine receptors. It is present in antitussives, under the trade name Hycodan, in combination with hydrocodone (dihydrocodeinone) bitartrate indicated for the symptomatic relief of cough as oral tablets or solutions. Homatropine is included in subtherapeutic amounts as homatropine methylbromide to discourage deliberate overdosage. Homatropine hydrobromide has been administered as ophthalmic solutions as a cycloplegic to temporarily paralyze accomodation, and to induce mydriasis (the dilation of the pupil); however such therapeutic use has not been approved by the FDA to be safe and effective.