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

This study has been completed.
National Institute of Mental Health (NIMH)
Dartmouth-Hitchcock Medical Center
Commonwealth Research Center, Massachusetts
Eli Lilly and Company
Information provided by (Responsible Party):
AlanGreen, National Institute of Mental Health (NIMH) Identifier:
First received: September 10, 2005
Last updated: April 6, 2015
Last verified: April 2015
This study will determine the effectiveness of clozapine versus olanzapine in treating people with schizophrenia that has not improved with treatment.

Condition Intervention Phase
Drug: Clozapine
Drug: Olanzapine
Phase 4

Study Type: Interventional
Study Design: Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single Blind (Outcomes Assessor)
Primary Purpose: Treatment
Official Title: Clozapine vs. Olanzapine: An Effectiveness Study

Resource links provided by NLM:

Further study details as provided by Harvard Medical School:

Primary Outcome Measures:
  • Changes in quality of life.

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

Enrollment: 38
Study Start Date: August 1998
Study Completion Date: June 2002
Primary Completion Date: June 2002 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Active Comparator: Clozapine
Clozapine or olanzapine in treatment resistant schizophrenia
Drug: Clozapine
Active Comparator: olanzapine
clozapine or olanzapine in treatment resistant schizophrenia
Drug: Olanzapine

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.

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
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Please refer to this study by its identifier: 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) Identifier: NCT00169065     History of Changes
Other Study ID Numbers: R01MH049891 ( US NIH Grant/Contract Award Number )
Study First Received: September 10, 2005
Last Updated: April 6, 2015

Keywords provided by Harvard Medical School:

Additional relevant MeSH terms:
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