Improved P50 Auditory Gating With Ondansetron in Medicated Schizophrenia Patients.
Adler, Lawrence E. M.D.; Cawthra, Ellen M. R.N.; Donovan, Kara A. M.P.H.; Harris, Josette G. Ph.D.; Nagamoto, Herbert T. M.D.; Olincy, Ann M.D.; Waldo, Merilyne C. Ph.D.
[Report] American Journal of Psychiatry. 162(2):386-388, February 2005.

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Objective: Most schizophrenia patients have a deficit in auditory sensory gating, which appears to be mediated by the [alpha]-7 nicotinic receptor, that is not improved with conventional antipsychotic treatment. This study examined the effects of ondansetron, a highly selective 5-HT3 antagonist, on the P50 auditory evoked potential.

Method: Eight medicated outpatients with schizophrenia were given either ondansetron (16 mg) or placebo in a double-blind, placebo-controlled design. Evoked potentials were recorded at baseline and 1 hour, 2 hours, and 3 hours after receipt of drug.

Results: There was a highly significant improvement in P50 gating after ondansetron treatment. The maximal treatment difference was at 2 hours posttreatment (ondansetron: mean=41.4%, SD=39.7%; placebo: mean=80.2%, SD=21.3%).

Conclusions: Ondansetron significantly enhanced P50 auditory gating in schizophrenia patients treated with typical antipsychotics.

Copyright (C) 2005 American Psychiatric Association.