Monitoring of haloperidol serum levels and it's clinical significance.

Haloperidol serum levels were determined by the recently developed radioimmunoassay technique to elucidate the relationship between serum levels and clinical effects and that between serum levels and adverse effects. The serum levels of haloperidol in divided daily doses schedule reached to the steady state more rapidly (within 7 days) than in single dose schedule. The single daily dose schedule showed significantly wider diurnal variation than the divided daily doses schedule. No remarkable differences in serum concentration was noted between different types of oral haloperidol preparation (liquid, granule, tablet). No definite relationship was established between the serum concentration of haloperidol and incidence of tardive dyskinesia. No definite positive relationship between clinical effects and serum concentration of haloperidol could obtained.