ATC Group: N04A Anticholinergic agents

Benzatropine possesses both anticholinergic and antihistaminic effects, although only the former have been established as therapeutically significant in the management of parkinsonism.

Biperiden is a predominantly centrally acting anti-cholinergic. It has a peripheral effect, which is low in comparison to atropine. Biperiden binds competitively to peripheral and central muscarinic receptors (primarily M1).

Orphenadrine, which is a congener of diphenhydramine without sharing its soporific effect, is an anti-muscarinic agent. Orphenadrine is used as the hydrochloride in the symptomatic treatment of Parkinsonism.

Trihexyphenidyl is an anticholinergic agent. It is an antispasmodic drug which exerts a direct inhibitory effect on the parasympathetic nervous system. It diminishes salivation, increases the heart rate, dilates the pupils and reduces spasm of smooth muscle.