Haloperidol blood levels and clinical effects

Abstract

This study explored the relationships between plasma levels and the clinical effects of haloperidol in 176 acutely exacerbated schizophrenic or schizoaffective patients. After a single-blind placebo period of 1 week (period 1), they entered the double-blind period 2 randomly assigned to one of three plasma levels of haloperidol: low (2 to 13 ng/mL), medium (13.1 to 24 ng/mL), or high (24.1 to 35 ng/mL). Patients whose conditions did not improve in period 2 continued on one of the three haloperidol levels (period 3). Periods 2 and 3 lasted 6 weeks each. Only minor differences in clinical responses were noted among the three levels of haloperidol. These results imply that low or moderate doses of neuroleptics are appropriate for many acutely psychotic patients.