Effects of raclopride treatment on plasma and CSF HVA: relationships with clinical improvement in male schizophrenics.

Thirty-two acutely psychotic, male schizophrenic patients received raclopride, at 2, 6, or 12 mg/day, or haloperidol, 15 mg/day for 4 weeks after randomized, double-blind assignment. Twenty-six patients, including 19 who had been assigned one of the three doses of raclopride, completed the study. Raclopride, particularly at 12 mg/day, increased CSF homovanillic acid (HVA) at 4 weeks, and plasma HVA at 2 days, of treatment. The clinical response to raclopride was significantly correlated with plasma raclopride concentrations and baseline plasma HVA concentrations. Although raclopride is a substituted benzamide with atypical properties in animals, these results suggest that the doses of raclopride required for clinical efficacy and elevation of clinical indices of brain dopamine turnover are similar.