Benztropine
Benzatropine is tropane in which a hydrogen at position 3 is substituted by a diphenylmethoxy group (endo-isomer). An acetylcholine receptor antagonist, it is used (particularly as its methanesulphonate salt) in the treatment of Parkinson's disease, and to reduce parkinsonism and akathisia side effects of antipsychotic treatments. It has a role as an antiparkinson drug, a parasympatholytic, an antidyskinesia agent, a muscarinic antagonist and a oneirogen.