Clinical trial NCT00149734: Addition of Ondansetron to Ongoing Antipsychotic Treatment for Schizophrenia
Official title: Atypical Antipsychotics and P50 Sensory Gating
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: PHASE3
Conditions: Schizophrenia
Keywords: Schizophrenia
Ondansetron
P50 sensory gating
Evoked potentials
5-HT3 receptors
Atypical antipsychotics
Lead sponsor: University of Colorado, Denver
Sponsor class: OTHER
Collaborators: name: National Institute of Mental Health (NIMH)
First posted: 2005-09-08
Enrollment: 8
Sex: ALL
Minimum age (years): 18
Maximum age (years): 55
Standard ages: ADULT
Accepts healthy volunteers: no
Allocation: RANDOMIZED
Intervention model: CROSSOVER
Primary purpose: TREATMENT

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.

Eligibility criteria: Inclusion Criteria:

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

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

Primary outcomes:
measure: P50 Sensory Gating
timeFrame: Up to 3 hours
measure: Cognitive Testing
timeFrame: Measured at Months 3 and 6
Secondary outcomes:
Other outcomes:
Locations:
city: Denver
country: United States
facility: Denver VAMC
state: Colorado
Study officials:
affiliation: University of Colorado Health Sciences Center, VISN19 MIRECC
name: Lawrence E. Adler, MD
role: PRINCIPAL_INVESTIGATOR
References:
citation: Adler LE, Cawthra EM, Donovan KA, Harris JG, Nagamoto HT, Olincy A, Waldo MC. Improved p50 auditory gating with ondansetron in medicated schizophrenia patients. Am J Psychiatry. 2005 Feb;162(2):386-8. doi: 10.1176/appi.ajp.162.2.386.
citation: Adler LE, Olincy A, Cawthra EM, McRae KA, Harris JG, Nagamoto HT, Waldo MC, Hall MH, Bowles A, Woodward L, Ross RG, Freedman R. Varied effects of atypical neuroleptics on P50 auditory gating in schizophrenia patients. Am J Psychiatry. 2004 Oct;161(10):1822-8. doi: 10.1176/ajp.161.10.1822.