[Drug-induced movement disorders].

Many drugs have been known to cause movement disorders with different mechanisms of action. Most of these drugs interfere with dopaminergic transmission within the basal ganglia. However, numerous other drugs are capable of producing movement disorders, whose mechanism is not at all clearly understood. Neuroleptic drugs-induced extrapyramidal symptoms such as dystonia, akathisia, parkinsonism have been related to sudden imbalance between the striatal dopamine and cholinergic systems, causing a relative preponderance of acetylcholine. Some calcium channel blockers and H2 blockers induced or aggravated parkinsonism and other extrapyramidal symptoms. It has been suggested that calcium channel blockers-induced extrapyramidal symptoms are much more common in elderly patients. In H2 blockers induced movement disorders, renal and liver dysfunction is the risk factor of them, but the mechanism is not clearly understood.