Drug-induced and tardive movement disorders.

Drug-induced and tardive movement disorders represent a large number of extrapyramidal disorders seen in neurologic practice. Iatrogenically induced, most commonly by neuroleptics, these disorders can be characterized by any abnormal body movement including tremor, chorea, athetosis, dyskinesias, dystonia, myoclonus, tics, ballismus or akathisia. Parkinsonism, dyskinesias and dystonia tend to be the most common. Management of patients with drug-induced or tardive syndromes is complex. Prognosis is frequently poor as patients usually need the offending agent to manage their underlying psychiatric or medical problem. Neuroleptics and other drugs known commonly to cause movement disorders should be used cautiously and significant consideration of all risks and benefits measured before initiating therapy.