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Olanzapine Versus Clozapine in Treatment Refractory Schizophrenia

This study has been completed.
Information provided by:
Vanderbilt University Identifier:
First received: September 13, 2005
Last updated: NA
Last verified: September 2005
History: No changes posted
The study involves a six-month, double-blind protocol during which eighty patients, across three sites around the country, will be randomly assigned to receive clozapine or olanzapine. The specific aims of the study are to evaluate the relative effects of olanzapine and clozapine on clinical outcomes and cognition in patients diagnosed with schizophrenia or schizoaffective disorder who have demonstrated resistance to treatment in the past.

Condition Intervention
Schizoaffective Disorder
Drug: olanzapine vs. clozapine

Study Type: Interventional
Study Design: Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double-Blind
Primary Purpose: Treatment

Resource links provided by NLM:

Further study details as provided by Vanderbilt University:

Primary Outcome Measures:
  • There has not been an adequate of test of whether olanzapine is as effective as clozapine in treatment
  • resistant patients. Several recent studies suggest olanzapine may be effective in some clozapine responders as well as in treatment resistant patients. A head to head comparison is needed to clarify the relative efficacy

Estimated Enrollment: 80
Study Start Date: May 2000
Estimated Study Completion Date: February 2004

Ages Eligible for Study:   18 Years to 60 Years   (Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  1. Patients will be males and females, ages 18-60, with a definite diagnosis by DSM-IV criteria of schizophrenia (any subtype) or schizoaffective disorder.
  2. 2) All participants will be refractory according to the Kane et al (1988) criteria, with modification on the number of drug trials to at least two neuroleptic drugs at adequate doses for periods > 3 months. The criteria of Kane et al. for treatment resistance are as follows: three or more trials with antipsychotic drugs of adequate dose and duration (this is usually 4-6 weeks). The original criteria involved three types of typical neuroleptic drugs. Now, it can include any antipsychotic drug other than clozapine. Olanzapine may have been tried but the dose must not have exceeded 30 mg/day.
  3. Subjects must have a PANNS-derived BPRS total score > 24 (0-6 scale) or BPRS positive subscale item score > 3 on at least two of the four items.
  4. Participants will be in generally good and stable physical health.
  5. Written informed consent will be obtained from all participants after a full explanation of the study and procedures. For those patients with a legal guardian, written informed consent will be obtained from the guardian, with verbal assent by the research subject.
  6. Since both clozapine and olanzapine are approved agents, no specific birth control will be required for females, but advice about birth control will be provided

Exclusion Criteria:

  1. Uncontrolled diabetes or hypertension.
  2. Cardiac conduction abnormality or uncontrolled arrhythmia.
  3. History of any blood dyscrasia, including leukemia.
  4. Significant active hepatic or renal disease, including chronic hepatitis.
  5. Clinically significant neurological disorder, including (but not limited to) Parkinson’s disease, multiple sclerosis, seizure disorder, intracranial mass lesion (note that the presence of tardive dyskinesia is not an exclusion for participants).
  6. Active cancer with or without chemotherapy within the last five years (not to include a completely excised basal cell carcinoma).
  7. Active endocrinological disorder (which does not include adequately treated hypothyroidism).
  8. Pregnancy or lactation.
  9. An active substance use disorder within the last six months.
  10. History of lack of response to an adequate trial of monotherapy with either clozapine or olanzapine in which the dose of clozapine must be > 600 mg/day or the dose of olanzapine must be > 20 mg/day; and the duration of treatment with either must be > 6 weeks.
  11. History of intolerance of clozapine or olanzapine, including blood dyscrasia
  Contacts and Locations
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Please refer to this study by its identifier: NCT00179231

Sponsors and Collaborators
Vanderbilt University
Principal Investigator: Herbert Y Meltzer, M.D. Vanderbilt University Medical Center
  More Information

Publications automatically indexed to this study by Identifier (NCT Number): Identifier: NCT00179231     History of Changes
Other Study ID Numbers: 990172
Study First Received: September 13, 2005
Last Updated: September 13, 2005

Additional relevant MeSH terms:
Psychotic Disorders
Schizophrenia Spectrum and Other Psychotic Disorders
Mental Disorders
Serotonin Antagonists
Serotonin Agents
Neurotransmitter Agents
Molecular Mechanisms of Pharmacological Action
Physiological Effects of Drugs
Antipsychotic Agents
Tranquilizing Agents
Central Nervous System Depressants
Psychotropic Drugs
GABA Antagonists
GABA Agents
Autonomic Agents
Peripheral Nervous System Agents
Gastrointestinal Agents
Serotonin Uptake Inhibitors
Neurotransmitter Uptake Inhibitors
Membrane Transport Modulators processed this record on April 27, 2017