History and Discovery | Structure–Activity Relations | Pharmacological Profile | Pharmacokinetics and Disposition | Indications and Efficacy | Mechanism of Action, Side Effects, and Drug–Drug
Benztropine was synthesized by uniting the tropine portion
of atropine with the benzhydryl portion of diphenhydramine hydrochloride.
Benztropine was found to be effective in the treatment of 302 patients
with Parkinson's disease (Doshay 1956). The
best results in the control of rigidity, contracture, and tremor
were obtained at doses of 1–4 mg qd for older patients
and 2–8 mg qd for younger ones. Doses of 15–30
mg qd caused excessive flaccidity in some patients, who became unable
to lift their arms or raise their heads off the bed. Subsequently,
benztropine was found to be effective for the treatment of NIP (Karn and Kasper 1959).