Benapryzine is a dialkylaminoethanol ester of diphenylacetic acid. It is a muscarinic cholinoceptor antagonist with negligible peripheral effects. Benapryzine in addition to its anti-acetylcholine action antagonizes both maximal electroshock and metrazol-induced convulsions in mice. This feature is not generally shown by anti-acetylcholine agents but is seen with orphenadrine. Side effects of benapryzine were rare. They are: drowsiness, dry mouth, confusion, disorientation, hallucinations and postural syncope with measurable postural hypotension. Benapryzine has been used as an antiparkinsonian agent.