Addition of Ondansetron to Ongoing Antipsychotic Treatment for Schizophrenia

Phase 3

Completed

• Conditions: Schizophrenia
• Interventions: Drug: Ondansetron followed by placebo; Drug: Placebo followed by Ondansetron

• Registration Number: NCT00149734
• Lead Sponsor: University of Colorado, Denver

Brief Summary

This study will examine the effects of ondansetron on auditory nerve activity in people with schizophrenia who are being treated with new antipsychotics.

Detailed Description

Schizophrenia is a devastating brain disorder. Most people with schizophrenia have difficulty filtering out unimportant auditory information. They have an inability to appropriately inhibit, or gate, sensory information that enters the ear. Standard treatments do not address this problem. When the drug ondansetron is taken in addition to typical antipsychotic drugs, P50 auditory gating improves. However, ondansetron has not been used with some of the newer, atypical antipsychotic drugs. This study will evaluate the effect of combining ondansetron with newer, atypical antipsychotic drugs on P50 auditory gating.

Participants in this double-blind study will be randomly assigned to receive either ondansetron or placebo for 3 months. Upon completion of the first 3 months, participants will be crossed over to receive the other treatment for an additional 3 months. All participants will also take an atypical antipsychotic drug, including olanzapine, quetiapine, or aripiprazole. Auditory gating will be assessed using computerized cognitive testing and functional magnetic resonance imaging (fMRI) at baseline and Months 3 and 6. Vital signs and evoked potentials will be assessed at Weeks 1, 3, and 6. Clinical symptoms and cognitive abilities will also be evaluated to determine the effectiveness of ondansetron.

Study Timeline

• Study Start: 2005-01
• Study First Submitted: 2005-09-06
• Study First Submitted QC: 2005-09-06
• Study First Posted: 2005-09-08
• Primary Completion: 2010-05
• Study Completion: 2010-05
• Status Verified: 2021-07
• Results First Submitted: 2021-07-20
• Results First Submitted QC: 2021-07-20
• Last Update Submitted: 2021-07-20
• Results First Posted: 2021-08-13
• Last Update Posted: 2021-08-13

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 8

Inclusion Criteria

• Meets DSM-IV criteria for schizophrenia
• Stable, chronic schizophrenia
• Currently taking atypical medications
• Use of effective form of contraception throughout study

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Exclusion Criteria

• History of any alcohol or drug abuse within 3 months of study start date
• Any other major neurological disorders
• History of or current head trauma
• Any medical conditions affecting the central nervous system
• Current epilepsy, asthma, migraine headache, previous myocardial infarction, stroke, diabetes, hypertension, narrow angle glaucoma, or neuromuscular illnesses
• Pregnant

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Study & Design

• Study Type: INTERVENTIONAL
• Study Design: CROSSOVER

Arm && Interventions

Group	Intervention	Description
Ondansetron followed by placebo	Ondansetron followed by placebo	Participants will take ondansetron then placebo plus an atypical antipsychotic drug
Placebo followed by Ondansetron	Placebo followed by Ondansetron	Participants will take placebo then ondansetron plus an atypical antipsychotic drug

Primary Outcome Measures

Name	Time	Method
P50 Sensory Gating	Up to 3 hours	P50 Sensory Gating as measured by evoked potentials (response to stimuli, in this case, clicking sounds).The P50 potential was identified and measured using a computer algorithm. The amplitude of the P50 test wave was divided by the amplitude of the P50 conditioning wave, expressed as a percentage: the P50 ratio. Lower P50 ratios represent better outcomes.
Cognitive Testing	Measured at Months 3 and 6

Trial Locations

Locations (1)

Denver VAMC; 🇺🇸 Denver, Colorado, United States