Tiapride: effects on tardive dyskinesia and on prolactin plasma concentrations.

In a placebo-controlled double-blind crossover study of 21 patients chronically treated with neuroleptics and suffering from tardive dyskinesia, tiapride (600 mg/day, mean plasma level: 682 ng/ml) exhibited a transient efficacy during 12 weeks of treatment, most distinct in the 6th week (p less than 0.01). Tiapride induced an increase of prolactin plasma levels, on the average, from 1,195 to 2,179 microIU/ml (p less than 0.01). Tiapride was well tolerated. Increase of parkinsonism was only mild and not significant. The results underline the difficulty in treating tardive dyskinesia and, thus, confirm the importance of prevention.