20th July 2023

Drug-Induced Parkinsonism

This is the second most common aetiology of Parkinsonism and is usually caused by medications which antagonise dopamine receptors in the basal ganglia. Culprit medications include antipsychotics, stimulants, GI prokinetics or calcium channel blockers. Usually, the symptoms should improve if the causative medication is stopped, although it can take up to 18 months to do so. If the medication cannot be stopped, it should be reduced where possible. Alternative treatment options are anticholinergics, such as procyclidine.

Clinical symptoms include bilateral and symmetrical Parkinsonism without a resting tremor; however, in practice, a significant portion of patients present with an asymmetrical and resting tremor.