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

Pimozide Augmentation of Clozapine in Schizophrenia

Status
Completed
Phases
Phase 4
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT00158223
Enrollment
76
Registered
2005-09-12
Start date
2004-10-31
Completion date
2009-02-28
Last updated
2015-04-09

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Schizophrenia, Psychotic Disorders

Keywords

Schizophrenia, Clozapine, Treatment, Combination, Unresponsive, Schizoaffective Disorders

Brief summary

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

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.

Interventions

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.

DRUGPlacebo

Active drug and placebo will be encapsulated in an identical fashion. The placebo capsule will be made to match in appearance and weight. There will be flexible 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.

Sponsors

National Institute of Mental Health (NIMH)
CollaboratorNIH
Icahn School of Medicine at Mount Sinai
Lead SponsorOTHER

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
QUADRUPLE (Subject, Caregiver, Investigator, Outcomes Assessor)

Eligibility

Sex/Gender
ALL
Age
18 Years to 65 Years
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)

Design outcomes

Primary

MeasureTime frameDescription
Positive Syndrome Scale (PANSS) Total ScoreVariable change from baseline to week 12Severity of positive schizophrenic symptoms The Positive Syndrome Scale of the PANSS is comprised of seven items measuring positive such symptoms such as hallucinations, delusions, grandiosity, etc. Each item is scored on a 7 point scale of that particular symptom's severity, ranging from 1 = absent, 2 = minimal, 3 = mild, 4 = moderate, 5 = moderate severe, 6 = severe, and 7 = extreme. The PANSS Positive Subscale seven items has a range of a summed score from 7 (absent) to 49 (extreme psychopathology). Therefore, the higher the score, the more severe the symtpoms.
Negative Syndrome Scale (PANSS) Total ScoreVariable change from baseline to week 12Severity of negative schizophrenic symptoms, The Negative Syndrome scale is compromised of seven items, each scored on severity with numeric assignments ranging from 1 = absent, 2 = minimal, 3 = mild, 4 = moderate, 5 = moderate severe, 6 = severe, and 7 = extreme. The items which comprise the Negative Syndrome Scale of the PANSS measure things such as emotional withdrawal, apathy, difficulty in abstract thinking, etc. The seven items which comprise the PANSS Negative Subscale has an aggregate range of 7 (absent) to 49 (extreme psychopathology), a higher score indicating more severe symptoms.

Secondary

MeasureTime frameDescription
Clinical Global Impression of Change (CGIC)variable change from baseline to week 12The Clinical Global Impression-improvement (CGI-improvement) scale is a research rating tool, developed for use in NIMH-sponsored clinical trials provides a brief assessment of the clinician's view of the patient's overall clinical improvement prior to and after initiating a study medication. The CGI-change is rated on a seven point scale ranging from 1= very much improved since the initiation of treatment to 7=very much worse since the initiation of treatment. Therefore, a lower score indicates more improvement in symptoms over time.

Countries

United States

Participant flow

Recruitment details

Subjects recruited from inpatient and outpatient treatment settings at Mount Sinai Hospital, Pilgrim Psychiatric Center and Manhattan Psychiatric Center in New York.

Pre-assignment details

16 subjects were excluded during the 4-week symptom stability-screening period before randomization because of withdrawal of consent or a failure to meet inclusion and exclusion criteria. Seven additional subjects were randomized to a haloperidol adjunctive pilot study.

Participants by arm

ArmCount
Placebo
Participants received encapsulated placebo made to match active drug
28
Pimozide
Participants received pimozide flexible dosing
25
Total53

Baseline characteristics

CharacteristicPlaceboPimozideTotal
Age, Continuous44.4 years
STANDARD_DEVIATION 8.7
45.5 years
STANDARD_DEVIATION 10.2
44.9 years
STANDARD_DEVIATION 9.5
Sex: Female, Male
Female
8 Participants4 Participants12 Participants
Sex: Female, Male
Male
20 Participants21 Participants41 Participants
Treatment Setting
Inpatient
19 participants15 participants34 participants
Treatment Setting
Outpatient
9 participants10 participants19 participants

Adverse events

Event typeEG000
affected / at risk
EG001
affected / at risk
deaths
Total, all-cause mortality
— / —— / —
other
Total, other adverse events
5 / 283 / 25
serious
Total, serious adverse events
0 / 280 / 25

Outcome results

Primary

Negative Syndrome Scale (PANSS) Total Score

Severity of negative schizophrenic symptoms, The Negative Syndrome scale is compromised of seven items, each scored on severity with numeric assignments ranging from 1 = absent, 2 = minimal, 3 = mild, 4 = moderate, 5 = moderate severe, 6 = severe, and 7 = extreme. The items which comprise the Negative Syndrome Scale of the PANSS measure things such as emotional withdrawal, apathy, difficulty in abstract thinking, etc. The seven items which comprise the PANSS Negative Subscale has an aggregate range of 7 (absent) to 49 (extreme psychopathology), a higher score indicating more severe symptoms.

Time frame: Variable change from baseline to week 12

ArmMeasureValue (MEAN)Dispersion
PlaceboNegative Syndrome Scale (PANSS) Total Score-1.59 units on a scaleStandard Deviation 4.46
PimozideNegative Syndrome Scale (PANSS) Total Score0.65 units on a scaleStandard Deviation 4.65
Primary

Positive Syndrome Scale (PANSS) Total Score

Severity of positive schizophrenic symptoms The Positive Syndrome Scale of the PANSS is comprised of seven items measuring positive such symptoms such as hallucinations, delusions, grandiosity, etc. Each item is scored on a 7 point scale of that particular symptom's severity, ranging from 1 = absent, 2 = minimal, 3 = mild, 4 = moderate, 5 = moderate severe, 6 = severe, and 7 = extreme. The PANSS Positive Subscale seven items has a range of a summed score from 7 (absent) to 49 (extreme psychopathology). Therefore, the higher the score, the more severe the symtpoms.

Time frame: Variable change from baseline to week 12

ArmMeasureValue (MEAN)Dispersion
PlaceboPositive Syndrome Scale (PANSS) Total Score-1.05 units on a scaleStandard Deviation 2.98
PimozidePositive Syndrome Scale (PANSS) Total Score-1.30 units on a scaleStandard Deviation 2.56
Secondary

Clinical Global Impression of Change (CGIC)

The Clinical Global Impression-improvement (CGI-improvement) scale is a research rating tool, developed for use in NIMH-sponsored clinical trials provides a brief assessment of the clinician's view of the patient's overall clinical improvement prior to and after initiating a study medication. The CGI-change is rated on a seven point scale ranging from 1= very much improved since the initiation of treatment to 7=very much worse since the initiation of treatment. Therefore, a lower score indicates more improvement in symptoms over time.

Time frame: variable change from baseline to week 12

ArmMeasureValue (MEAN)Dispersion
PlaceboClinical Global Impression of Change (CGIC)-0.35 units on a scaleStandard Deviation 0.57
PimozideClinical Global Impression of Change (CGIC)-0.15 units on a scaleStandard Deviation 4.97

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026