Neuroleptic treatment in a gerontopsychiatric department: Serum concentrations of perphenazine and haloperidol

Serum concentrations of perphenazine and haloperidol were studied in 48 patients (age, 62-96 years) admitted to a gerontopsychiatric department with a well-defined catchment area and using strict admission criteria. Therapeutic drug monitoring is used on a regular basis in drug treatment of the elderly. The indications for treatment with perphenazine and haloperidol were manic symptoms, hallucination or delusion, or behavioral disturbances, especially aggression. Clinically significant improvement was observed in 80% of the patients. Perphenazine and haloperidol were prescribed at fairly low doses-that is, mean, 7.6 (range, 2-14) mg/24 h, and mean, 3.3 (range, 1-7.5) mg/24 h, respectively. The mean serum concentration of perphenazine was 2.4 nmol/1 (SD, 2.6) and of haloperidol 4.5 nmol/1 (SD, 2.0). Thus, all patients receiving haloperidol treatment and 52% receiving perphenazine had serum concentrations below the therapeutic range recommended for treatment of psychotic patients-that is, schizophreniform psychoses. The limitations of a naturalistic study should be underlined, but our results strongly indicate that a significant proportion of gerontopsychiatric patients can be appropriately treated with perphenazine and haloperidol at low dosages.