Drug-induced Parkinsonism and abnormal involuntary movements

Abstract

Motor side effects emerging from the use of neuroleptics have been recognised since their first use in the 1950s. There is however an increasing awareness that other drug classes (in particular other psychotropic drugs and calcium channel blockers) are also implicated in the genesis of parkinsonism and other abnormal involuntary movements. Second-generation antipsychotics have a reduced propensity to lead to these side effects but may still cause problems in high-risk groups like people with dementia. Treatments for the various movement problems (parkinsonism, dyskinesia and dystonias) vary dependent upon the symptoms that predominate, given the differential balance between dopaminergic and cholinergic dysfunction between these three side effect clusters. Though stopping or switching the offending drug is always the first option, newer drugs for the treatment of Alzheimer's disease whose effects are upon cholinergic transmission are showing some promise as an adjunct to treatments for motor side effects.