Olanzapine acute administration in schizophrenic patients increases delta sleep and sleep efficiency

Background: A delta sleep deficit has been observed in schizophrenic patients. Olanzapine is a novel atypical antipsychotic agent with affinity at dopaminergic, serotonergic, muscarinic, adrenergic and histaminergic binding sites. The present study was designed to analyze a sleep promoting effect reported for olanzapine. Methods: Twenty schizophrenic patients (DSM-IV) were studied, who were drug free and inpatients. Patients slept for 5 consecutive nights in the sleep unit as follows: one acclimatization night; two baseline nights (the first for sleep disorder screenings); and two olanzapine nights (10 mg olanzapine, one hour before sleep onset). Results: Sleep continuity variables and total sleep time showed an overall improvement with olanzapine. Waking time was reduced since the first night of olanzapine administration. The main sleep architecture changes were: reduction in sleep stage 1, while sleep stage 2 and delta were significantly enhanced. Rapid eye movement density was also increased by the second olanzapine night. Conclusions: Total sleep improvement was due to the increase in sleep stages 2 and delta sleep. This may be related to serotonergic antagonistic properties of olanzapine. Olanzapine seems to have a sleep promoting effect in schizophrenic patients.