1. CNS— uses muscarinic agents

1. CNS—Scopolamine is standard therapy for motion sickness; it is one of the most effective agents available for this condition. A transdermal patch formulation is available. Benztropine, biperiden, and trihexyphenidyl are representative of several antimuscarinic agents used in parkinsonism. Although not as effective as levodopa, these agents may be useful as adjuncts or when patients become unresponsive to levodopa. Benztropine is sometimes used parenterally to treat acute dystonias caused by first generation antipsychotic medications.