Drug-induced dystonia.

Among 1,152 psychiatric inpatients who received a phenothiazine, a butyrophenone, or a thioxanthene, 116 developed dystonia attributed to one or more of these drugs. The highest frequencies of dystonia occurred among recipients of haloperidol and the long-acting injectable fluphenazines. For all patients at risk, dystonia was more common in men and in younger patients. For chlorpromazine, high doses, male sex, and low age were each positively associated with dystonia.