Biperiden withdrawal in schizophrenic inpatients receiving long-term antipsychotic medication

In a double-blind, 4 week study, 42 chronic schizophrenic inpatients receiving antipsychotic and antiparkinsonian (AP) drugs for greater than 3 months were either switched to placebo or maintained on biperiden. In the majority of the patients no clinically apparent discomfort was observed, and only two of 21 placebo patients developed extrapyramidal side effects (EPS) severe enough to require resumption of AP therapy. No significant increase was shown in most items on EPS. Our data suggest that for the majority of patients on long-term AP medication AP drugs should be prescribed only when EPS develop.