Trihexyphenidyl is used for the symptomatic treatment of
Parkinson's disease in mono and combination therapy. It is active in
postencephalitic,
arteriosclerotic, and
idiopathic forms. The drug is also commonly used to treat
extrapyramidal side effects occurring during
antipsychotic treatment. It reduces the frequency and duration of
oculogyric crises as well as of
dyskinetic movements and spastic contractions. Trihexyphenidyl may improve
psychotic depression and mental inertia frequently associated with Parkinson's disease and symptomatic problems caused by antipsychotic treatment