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Effectiveness of Clozapine Versus Olanzapine for Treatment-resistant Schizophrenia (COES)

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details.
ClinicalTrials.gov Identifier: NCT00169065
Recruitment Status : Completed
First Posted : September 15, 2005
Last Update Posted : April 7, 2015
Information provided by (Responsible Party):

Study Description
Brief Summary:
This study will determine the effectiveness of clozapine versus olanzapine in treating people with schizophrenia that has not improved with treatment.

Condition or disease Intervention/treatment Phase
Schizophrenia Drug: Clozapine Drug: Olanzapine Phase 4

Detailed Description:
This is a two-year open-label, randomized trial of the comparative effectiveness of clozapine versus olanzapine in patients with treatment refractory schizophrenia. The objective is to determine whether in a naturalistic setting olanzapine is a logical treatment choice (before using the more toxic clozapine) for some treatment refractory patients.

Study Design

Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 38 participants
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single (Outcomes Assessor)
Primary Purpose: Treatment
Official Title: Clozapine vs. Olanzapine: An Effectiveness Study
Study Start Date : August 1998
Primary Completion Date : June 2002
Study Completion Date : June 2002

Resource links provided by the National Library of Medicine

MedlinePlus related topics: Schizophrenia
U.S. FDA Resources

Arms and Interventions

Arm Intervention/treatment
Active Comparator: Clozapine
Clozapine or olanzapine in treatment resistant schizophrenia
Drug: Clozapine
Active Comparator: olanzapine
clozapine or olanzapine in treatment resistant schizophrenia
Drug: Olanzapine

Outcome Measures

Primary Outcome Measures :
  1. Changes in quality of life.

Secondary Outcome Measures :
  1. Symptom measures, neurological side effects, neuropsychological performance, patient satisfaction and burden on the family.

Eligibility Criteria

Information from the National Library of Medicine

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Ages Eligible for Study:   20 Years to 60 Years   (Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • Age 20-60 years;
  • Diagnosis of treatment refractory schizophrenia or schizoaffective disorder;
  • BPRS score > 21 (0-6) scale;
  • Either two 6-8 week trials of typical neuroleptics given at a dosage of 600 mg/day of CPZ or its equivalent or one 6-8 week trial of an atypical antipsychotic at a reasonable dose (i.e. risperidone 4-6 mg/day);
  • The patient (or the patient's authorized legal representative) must understand the nature of the study and sign the informed consent;
  • Clinically appropriate for clozapine or olanzapine

Exclusion Criteria:

  • Current substance abuse;
  • Suicide or homicide risk;
  • Pregnancy or lactation;
  • History of seizures or blood dyscrasias
Contacts and Locations

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT00169065

United States, Massachusetts
Commonwealth Research Center
Jamaica Plain, Massachusetts, United States, 02130
Sponsors and Collaborators
Harvard Medical School
National Institute of Mental Health (NIMH)
Dartmouth-Hitchcock Medical Center
Commonwealth Research Center, Massachusetts
Eli Lilly and Company
Principal Investigator: Alan I Green, MD Harvard Medical School
More Information

Responsible Party: AlanGreen, Chair, Department of Psychiatry Geisel School of Medicine at Dartmouth, National Institute of Mental Health (NIMH)
ClinicalTrials.gov Identifier: NCT00169065     History of Changes
Other Study ID Numbers: R01MH049891 ( U.S. NIH Grant/Contract )
First Posted: September 15, 2005    Key Record Dates
Last Update Posted: April 7, 2015
Last Verified: April 2015

Keywords provided by AlanGreen, National Institute of Mental Health (NIMH):

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