Despite the widespread use of chlorpromazine in psychiatric treatment no information is available concerning the blood levels of the drug in man. In animals, a report by Dubost and Pascal1 relates blood concentrations of chlorpromazine in dogs and rabbits to oral and intravenous dosage.This paucity of information led to a study of the blood levels of chlorpromazine in hospitalized chronically ill psychotic male patients who were receiving treatment with the drug. Blood level determinations were made after intramuscular and oral administration, following drug-free intervals and at the initiation of treatment, and during varying periods of drug therapy with increasing dosages of chlorpromazine.
Seven chronically ill, male schizophrenic patients, ranging in age from 19 to 53 and housed on the same ward, were studied. These were the same patients utilized in the study of the urinary excretion of chlorpromazine and its