Clozapine for Cannabis Use in Schizophrenia
CLOCS
Clozapine for Cannabis Use Disorder in Schizophrenia
2 other identifiers
interventional
49
1 country
9
Brief Summary
Many individuals with schizophrenia also suffer from marijuana addiction that worsens their problems related to schizophrenia. Most of the medications prescribed for schizophrenia have no effect on reducing marijuana use. Preliminary data suggests that clozapine, an atypical antipsychotic, may limit marijuana use in people diagnosed with schizophrenia, but it is not commonly used due to its side effects and is reserved for people who do not respond to other antipsychotic medications. In the proposed study, 132 individuals who are diagnosed with both schizophrenia and a cannabis use disorder will be randomized to a 12-week treatment course with either clozapine or risperidone (another commonly prescribed antipsychotic medication) to test the hypothesis that patient treated with clozapine will have decreased cannabis use as compared to patients treated with risperidone. Should this study indicate that clozapine will lessen marijuana use in persons diagnosed with schizophrenia more than risperidone, it will provide evidence needed to begin to shift clinical practice toward its use in this population.
Trial Health
Trial Health Score
Automated assessment based on enrollment pace, timeline, and geographic reach
participants targeted
Target at P25-P50 for phase_4 schizophrenia
Started May 2013
Typical duration for phase_4 schizophrenia
9 active sites
Health score is calculated from publicly available data and should be used for screening purposes only.
Trial Relationships
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Study Timeline
Key milestones and dates
First Submitted
Initial submission to the registry
July 11, 2012
CompletedFirst Posted
Study publicly available on registry
July 13, 2012
CompletedStudy Start
First participant enrolled
May 1, 2013
CompletedPrimary Completion
Last participant's last visit for primary outcome
March 29, 2017
CompletedStudy Completion
Last participant's last visit for all outcomes
March 29, 2017
CompletedResults Posted
Study results publicly available
December 26, 2019
CompletedMay 5, 2020
April 1, 2020
3.9 years
July 11, 2012
December 12, 2019
April 27, 2020
Conditions
Keywords
Outcome Measures
Primary Outcomes (2)
Average Over Time of Intensity of Cannabis Use (Used to Evaluate Treatment Efficacy)
Intensity of cannabis use is obtained each week retrospectively as the number of joints smoked during the prior week (assessed using the Timeline Followback). Mixed models are used to obtain estimates of efficacy from the partial data provided by each subject while adherent to assigned treatment (under the 'missing at random' assumption). The 'explanatory' estimands (target of the mixed model estimation) are defined in terms of population quantities that would have occurred had all subjects remained on assigned treatment throughout the study. The point estimate for each arm is reported under Number.
12 weeks
Average Over Time of Frequency of Cannabis Use
Frequency of cannabis use is obtained each week retrospectively as the number of days of cannabis use during the prior week (assessed using the Timeline Followback). Mixed models are used to obtain estimates of efficacy from the partial data provided by each subject while adherent to assigned treatment (under the 'missing at random' assumption). The 'explanatory' estimands (target of the mixed model estimation) are defined in terms of population quantities that would have occurred had all subjects remained on assigned treatment throughout the study. The point estimate for each arm is reported under Number.
12 weeks
Study Arms (2)
Clozapine
EXPERIMENTALThe blinded CLOZ will be titrated on a recommended standard schedule, supervised by a study physician (or other prescriber) who can make the necessary adjustments to account for symptom control and tolerability. The titration is recommended to begin at 12.5 mg and then increase while the open-label base antipsychotic is tapered with a recommended goal of decreasing the base antipsychotic by 25% each week. If clinically tolerated, the target dose of CLOZ is 400 mg/day.
Risperidone
ACTIVE COMPARATORThe blinded RISP will also be titrated in the first weeks, using a titration schedule, with a target dose of 4 mg/day, while the open label base antipsychotic is tapered in a similar fashion.
Interventions
Clozapine: target dose of 400mg per day with a maximum dose of 550mg per day
Clozapine: target dose of 4mg per day with a maximum dose of 6mg per day
Eligibility Criteria
You may qualify if:
- Clinical diagnosis of schizophrenia
- Clinical diagnosis of a cannabis use disorder (abuse or dependence)
You may not qualify if:
- Pregnant,trying to become pregnant or nursing
- History of a seizure disorder
- Current treatment with clozapine or risperidone
- Contraindication to treatment with clozapine or risperidone
Contact the study team to confirm eligibility.
Sponsors & Collaborators
- Dartmouth-Hitchcock Medical Centerlead
- University of South Carolinacollaborator
- Michigan State Universitycollaborator
- University of Miamicollaborator
- University of Massachusetts, Worcestercollaborator
Study Sites (9)
CNS Network Inc
Garden Grove, California, 92845, United States
Pacific Research Partners
Oakland, California, 94607, United States
University of Miami
Miami, Florida, 33136, United States
Unversity of Massachusetts Medical School
Worcester, Massachusetts, 01605, United States
Michigan State University / Cherry Street Health Services
Grand Rapids, Michigan, 49503, United States
Dartmouth Hitchcock Medical Center
Lebanon, New Hampshire, 03756, United States
University of North Carolina/UNC Center for Excellence in Community Mental Health
Raleigh, North Carolina, 27610, United States
University of South Carolina
Columbia, South Carolina, 29203, United States
Rutland Regional Medical Center
Rutland, Vermont, 05701, United States
MeSH Terms
Conditions
Interventions
Condition Hierarchy (Ancestors)
Intervention Hierarchy (Ancestors)
Results Point of Contact
- Title
- Dr. Mary Brunette
- Organization
- Psychopharmacology Research Group
Study Officials
- STUDY CHAIR
Alan I Green, MD
Dartmouth College
Publication Agreements
- PI is Sponsor Employee
- No
- Restrictive Agreement
- No
Study Design
- Study Type
- interventional
- Phase
- phase 4
- Allocation
- RANDOMIZED
- Masking
- QUADRUPLE
- Who Masked
- PARTICIPANT, CARE PROVIDER, INVESTIGATOR, OUTCOMES ASSESSOR
- Purpose
- TREATMENT
- Intervention Model
- PARALLEL
- Sponsor Type
- OTHER
- Responsible Party
- SPONSOR
Study Record Dates
First Submitted
July 11, 2012
First Posted
July 13, 2012
Study Start
May 1, 2013
Primary Completion
March 29, 2017
Study Completion
March 29, 2017
Last Updated
May 5, 2020
Results First Posted
December 26, 2019
Record last verified: 2020-04