The Use of an Oral Opiate Antagonist in Schizophrenia

Abstract

Opiate receptor antagonists of the “pure” type include the parenterally administered naloxone and the orally effective naltrexone (Martin et al., 1973; Resnick et al., 1974). An early report suggested that the former decreased hallucinations in schizophrenic patients (Gunne et al., 1977). The latter is the subject of this review since it, like naloxone, competes with endorphins for opioid receptor sites (Greenstein et al., 1978). Naltrexone acts for approximately 72 hr (Martin et al., 1973) and seems to be particularly free of side effects and toxicity (Greenstein et al., 1976, 1978; Bradford and Kaim, 1977). This drug is rapidly and completely absorbed with peak plasma levels of parent compound in 1 hr and of active metabolite (β-naltrexol) in 2 hr without accumulation (Verebey et al., 1976). The use of naltrexone in schizophrenic patients was primarily an attempt to evaluate the role of endorphins and opiate cells in mental illness.