Pharmacokinetics of tiapride in patients with tardive dyskinesia and Huntington's disease.

The pharmacokinetics of tiapride were determined at steady-state in 5 patients with tardive dyskinesia and 2 patients with Huntington's disease given tiapride 100 mg t.i.d. for 7 days. The maximum serum concentration of tiapride of 1.47 +/- 0.35 micrograms/ml was reached after 1.4 +/- 0.67 h. The half-life time of elimination was 229 +/- 41 min. About 50% of the dose of tiapride was excreted unchanged by the kidney. Neither protein binding nor glucuronide, sulphate or acetyl conjugation was observed. Renal clearance in the patients appeared to be lower but the other pharmacokinetic parameters did not differ from previous findings in healthy young volunteers.