Abuse of the antiparkinson drugs: a review of the literature.

A review of the literature indicates that the anticholinergic antiparkinson drugs can be abused by some patients to achieve pleasurable effects ranging from a mild euphoria with increased sociability at the lower doses to a toxic anticholinergic psychosis with disorientation and hallucinations at higher doses. Trihexyphenidyl may have a greater potential for abuse but there has been no systematic data on this issue. While the abuse of these drugs may not be widespread, it is yet another factor arguing for their judicious use.