Effectiveness of Pimozide in Augmenting the Effects of Clozapine in the Treatment of Schizophrenia

The recruitment status of this study is unknown because the information has not been verified recently.
Verified October 2008 by National Institute of Mental Health (NIMH).
Recruitment status was  Recruiting
Information provided by:
National Institute of Mental Health (NIMH)
ClinicalTrials.gov Identifier:
First received: September 7, 2005
Last updated: October 23, 2008
Last verified: October 2008

This study will assess the effectiveness of pimozide in enhancing the effects of clozapine in the treatment of schizophrenia.

Condition Intervention Phase
Psychotic Disorders
Drug: Pimozide
Drug: Placebo
Phase 4

Study Type: Interventional
Study Design: Allocation: Randomized
Endpoint Classification: Safety/Efficacy Study
Intervention Model: Parallel Assignment
Masking: Double Blind (Subject, Caregiver, Investigator, Outcomes Assessor)
Primary Purpose: Treatment
Official Title: Pimozide Augmentation of Clozapine in Schizophrenia

Resource links provided by NLM:

Further study details as provided by National Institute of Mental Health (NIMH):

Primary Outcome Measures:
  • Positive and Negative Syndrome Scale (PANSS) total score [ Time Frame: Measured weekly for 12 weeks ] [ Designated as safety issue: Yes ]

Secondary Outcome Measures:
  • Clinical Global Impression of Change (CGIC) [ Time Frame: Measured weekly for 12 weeks ] [ Designated as safety issue: Yes ]

Estimated Enrollment: 64
Study Start Date: October 2004
Estimated Study Completion Date: February 2009
Estimated Primary Completion Date: February 2009 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Placebo Comparator: 2
Participants will receive encapsulted placebo made to match active drug
Drug: Placebo
Active drug and placebo will be encapsulated in an identical fashion. The placebo capsule will be made to match in appearance and weight. There eill be felixble dosing, allowing a minimum of 1 capsule per day to 4 capsules per day, in order to match the dosing range of the active treatment.
Other Name: Sugar Pill
Experimental: 1
Participants will receive pimozide flexible dosing
Drug: Pimozide
Each capsule of active treatment will contain 2 mg of pimozide. Dosing will be flexible and will range from a minimum of 2 mg per day to 8 mg per day. Dosing will begin at Week 1 with 1 capsule per day. This will be slowly titrated at a rate of 1 capsule per week to a maximum of 4 capsules depending upon clinical response and side effects.
Other Name: Orap

Detailed Description:

A significant number of schizophrenics exhibit partial or no response to typical antipsychotic medications. Clozapine has been shown to be more effective in treating schizophrenia than typical antipsychotic drugs. However, only an estimated 30% to 60% of people who are unresponsive to treatment with typical antipsychotics will respond to treatment with clozapine. Taking clozapine with pimozide, an antipsychotic drug, can increase clozapine's effects. However, sufficient research on this approach has not yet been performed. This study will assess the effectiveness of pimozide in enhancing the effects of clozapine in the treatment of schizophrenia.

Participants in this double-blind study will receive a stable dose of clozapine for eight weeks prior to enrollment. For the first 4 weeks following enrollment, baseline measurements will be taken. Once a week, participants will report to the study site, where symptom severity, cognitive ability, and functional status, including reading level, will be assessed. In addition, participants will receive a standard medical examination, which will include blood tests and an EKG. Upon completion of this initial phase, participants will be randomly assigned to one of two treatment groups: clozapine combined with pimozide; or clozapine combined with placebo. This phase will last for 12 weeks. Study visits will continue to occur weekly, and will be used to re-assess the measurements obtained during baseline. In addition, participants will have an EKG at each study visit for the first 4 weeks of treatment. All baseline measurements will be repeated in Week 12.


Ages Eligible for Study:   18 Years to 65 Years
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • Diagnosis of schizophrenia according to DSM-IV criteria
  • Any schizoaffective disorder or subtype
  • Score greater than 60 on the Positive and Negative Syndrome Scale (PANSS)
  • Currently taking clozapine
  • Score of four or higher on two or more items from the positive symptom subscale of the PANSS
  • Score of 4 or greater on the Clinical Global Impression (CGI) scale
  • Clozapine plasma level greater than 378 µg/ml
  • Stable dose of clozapine demonstrated to have been associated with a clozapine plasma level greater than 378 µg/ml for at least eight weeks
  • Able to read at an 8th grade level or above

Exclusion Criteria:

  • History of unstable coronary artery disease
  • Congestive heart failure
  • History of long Q-T syndrome
  • History of cardiac arrhythmia
  • History of cardiac conduction delay
  • Baseline QT correction score greater than 0.425 seconds
  • Liver disease
  • History of stroke
  • History of Neuroleptic Malignant Syndrome
  • Hypokalemia
  • Hypocalcemia
  • Current blindness, deafness, language difficulties, or any other disability which may prevent participation or cooperation in the study
  • Current suicidal or homicidal thoughts
  • Currently abusing psychoactive substances
  • Currently receiving antidepressants, thymoleptics, L-DOPA, buspirone, or antipsychotics other than clozapine (Valproic acid and Divalproex sodium are not criteria for exclusion)
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its ClinicalTrials.gov identifier: NCT00158223

Contact: Joseph I. Friedman, MD 631-761-3607

United States, New York
Manhattan Psychiatric Center Recruiting
New York, New York, United States, 10035
Contact: Frances Alcantara    646-672-6173    Marcffa@omh.state.ny.us   
Principal Investigator: Jean-Pierre I. Lindenmayer, MD         
The Mount Sinai Hospital Recruiting
New York, New York, United States, 10029
Contact: Mariangela Cavagna    212-659-9223    mariangela.cavagna@mssm.edu   
Principal Investigator: Joseph I. Friedman, MD         
Pilgrim Psychiatric Center Recruiting
W. Brentwood, New York, United States, 11717
Contact: Michelle Bergman    631-761-2717    PGMDMIL@omh.state.ny.us   
Principal Investigator: Joseph I. Friedman, MD         
Sponsors and Collaborators
Principal Investigator: Joseph I. Friedman, MD Mount Sinai School of Medicine
  More Information

Additional publications automatically indexed to this study by ClinicalTrials.gov Identifier (NCT Number):
Responsible Party: Joseph I. Friedman, Mount Sinai School of Medicine
ClinicalTrials.gov Identifier: NCT00158223     History of Changes
Other Study ID Numbers: R01 MH67806, DSIR 83-ATAP
Study First Received: September 7, 2005
Last Updated: October 23, 2008
Health Authority: United States: Federal Government

Keywords provided by National Institute of Mental Health (NIMH):
Schizoaffective Disorders

Additional relevant MeSH terms:
Psychotic Disorders
Mental Disorders
Schizophrenia and Disorders with Psychotic Features
Anti-Dyskinesia Agents
Antipsychotic Agents
Central Nervous System Agents
Central Nervous System Depressants
Dopamine Agents
Dopamine Antagonists
Molecular Mechanisms of Pharmacological Action
Neurotransmitter Agents
Pharmacologic Actions
Physiological Effects of Drugs
Psychotropic Drugs
Therapeutic Uses
Tranquilizing Agents

ClinicalTrials.gov processed this record on March 30, 2015