Plasma concentrations of haloperidol and prolactin and clinical outcome in acutely psychotic patients.

This study was aimed at disclosing possible relationships between short term therapeutic outcome and certain ranges in plasma concentrations of haloperidol and of prolactin. Acutely psychotic patients (n = 28) were diagnosed (by RDC) as schizophrenics acute subtype (n = 17), schizoaffectives manic type, acute subtype (n = 8) and manics (n = 3). Parenteral haloperidol was the pharmacological treatment mostly given; the dose was kept constant intraindividually but varied between patients from 5 to 40 mg/d (median 15 mg/d). Data for statistical analyses of possible psychobiological relationships were analyzed at 12 days (median) of haloperidol regimen, that is at a relatively early cut-off in treatment. Keeping the methodological difficulties in mind, certain ranges in plasma concentrations of haloperidol (16-26.9 mg/ml; (Fig. 1) and of prolactin (64-159.9 mg/ml; (Fig. 2) were found to be associated-statistically independently-with a favourable therapeutic outcome. The rate of recovery was best if a patient came to lie with both plasma levels within these therapeutic ranges (Fig. 3). It is concluded that the combination of pharmacological and neuroendocrinological techniques in psychiatric research may be of substantial use for clinical purposes.