Managing antipsychotic-induced parkinsonism

Notwithstanding the advent of clozapine and other 'atypical' antipsychotic agents, the conventional ('typical') antipsychotic agents remain in widespread use. Antipsychotic-induced parkinsonism is a highly prevalent adverse effect that may result in increased morbidity and noncompliance. Bedside examination is generally sufficient for the detection of the onset of parkinsonism and should be carried out frequently in the first 3 months of treatment. In addition to decreasing patient discomfort, monitoring for antipsychotic-induced parkinsonism also serves to identify the minimally effective dosage required for the individual patient. Several strategies are utilised in the management of antipsychotic-induced parkinsonism including dosage reduction, switching to other antipsychotic agents and the use of antiparkinsonian drugs such as anticholinergic agents and amantadine. Anticholinergic agents remain the mainstay of the pharmacological management of antipsychotic-induced parkinsonism in younger patients. Amantadine is a better tolerated agent for elderly patients, with similar efficacy to the anticholinergic agents. The routine use of prophylactic anticholinergics is not recommended and is clearly contraindicated in the elderly. An individualised risk-benefit assessment is necessary for the younger patient in whom prophylactic use of anticholinergic drugs is considered.