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Risperidone Treatment in Schizophrenia Patients Who Are Currently Taking Clozapine

This study has been completed.
ClinicalTrials.gov Identifier:
First Posted: March 17, 2003
Last Update Posted: May 9, 2017
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.
National Institute of Mental Health (NIMH)
Ortho-McNeil Janssen Scientific Affairs, LLC
Information provided by (Responsible Party):
University of Maryland
This study will determine whether adding the drug risperidone (Risperdal®) is more effective than placebo in treating schizophrenic patients who are taking the drug clozapine.

Condition Intervention Phase
Schizophrenia Drug: Placebo Drug: Risperdal Phase 4

Study Type: Interventional
Study Design: Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
Primary Purpose: Treatment
Official Title: Clozapine Treatment of Schizophrenic Patients

Resource links provided by NLM:

Further study details as provided by University of Maryland:

Primary Outcome Measures:
  • Brief Psychiatric Rating Scale (BPRS) [ Time Frame: Measured at baseline and every 2 weeks for 16 weeks ]
    Scale assesses psychotic symptoms on a 20-item scale. The severity of each item is rated on a continuous scale from 1-7, with 1 being the least severe and 7 being most severe.

Secondary Outcome Measures:
  • Neuropsychological Testing [ Time Frame: Measured at baseline and Week 16 ]

Enrollment: 65
Study Start Date: December 2001
Study Completion Date: December 2007
Primary Completion Date: December 2007 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Active Comparator: Active
Participants assigned to risperidone
Drug: Risperdal
Risperdal 4 mg per day for 16 weeks
Other Name: Risperidone
Placebo Comparator: Placebo
Participants assigned to placebo
Drug: Placebo
Placebo capsule daily for 16 weeks

Detailed Description:

Clozapine is the only antipsychotic drug that has been approved for treatment resistant patients with schizophrenia. However, up to 50% of patients treated with clozapine fail to respond and continue to exhibit clinically significant residual positive and negative symptoms and cognitive impairments. An emerging trend in treatment is the addition of a second antipsychotic drug. This study will determine if risperidone when given as adjunctive treatment is more effective than placebo in treating schizophrenic patients failing clozapine therapy.

Participants are randomly assigned to add either adjunctive risperidone or placebo to their current clozapine treatment in a single, daily dose for 16 weeks. Positive and negative symptoms, cognitive impairments, side effects of the treatment, anxiety, depression, hostility symptoms, and quality of life are assessed. Neurological tests, self administered questionnaires, and interviews are used to assess patients.


Information from the National Library of Medicine

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Ages Eligible for Study:   18 Years to 65 Years   (Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • DSM-IV criteria for schizophrenia or schizoaffective disorder
  • Current clozapine treatment
  • Moderate illness severity and inadequate positive symptom response to clozapine treatment
  • 6 month period of clozapine treatment with documented clozapine blood level greater than or equal to 350 ng/ml or clozapine and norclozapine blood level greater than or equal to 450 ng/ml

Exclusion Criteria:

  • Organic brain disorder
  • Mental retardation
  • Medical condition whose pathology or treatment could alter the presentation or treatment of schizophrenia or significantly increase the risk associated with the proposed treatment protocol
  • Pregnancy
  • DSM-IV criteria for current alcohol or substance dependence within the last 6 months or DSM-IV criteria for alcohol or substance abuse within the last month
  • Previously received adjunctive risperidone (at doses greater than or equal to 8 mg/day) with their clozapine treatment for greater than or equal to 6 weeks
  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): NCT00056498

United States, Maryland
Maryland Psychiatric Research Center
Baltimore, Maryland, United States, 21228
Sponsors and Collaborators
University of Maryland
National Institute of Mental Health (NIMH)
Ortho-McNeil Janssen Scientific Affairs, LLC
Principal Investigator: Robert W Buchanan, MD University of Maryland
  More Information

Publications automatically indexed to this study by ClinicalTrials.gov Identifier (NCT Number):
Responsible Party: University of Maryland
ClinicalTrials.gov Identifier: NCT00056498     History of Changes
Other Study ID Numbers: R01MH045074 ( U.S. NIH Grant/Contract )
First Submitted: March 14, 2003
First Posted: March 17, 2003
Results First Submitted: March 23, 2009
Results First Posted: July 16, 2012
Last Update Posted: May 9, 2017
Last Verified: March 2017

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
Dopamine Antagonists
Dopamine Agents
GABA Antagonists
GABA Agents