Treatment of Schizophrenia and Comorbid Cannabis Use Disorder: Comparing Clozapine to Treatment-as-Usual

NCT00498550 | Completed Phase 4 Results DMC

• 3 other identifiers: NCT00149955R01DA013196DPMCDA
• Study Type: interventional
• Target: 31
• Locations: 1 country
• Sites: 4

Brief Summary

Many individuals with schizophrenia also suffer from marijuana addiction. Clozapine, an atypical antipsychotic medication, may prove useful at preventing drug relapse in schizophrenic individuals who are seeking treatment for marijuana addiction. The purpose of this study is to compare the effectiveness of clozapine, vs. treatment-as-usual with other oral antipsychotics at reducing marijuana use in schizophrenic individuals.

Conditions

Schizophrenia; Dual Diagnosis; Schizoaffective Disorder; Psychotic Disorder; Cannabis Abuse

Keywords

Clozapine; Schizophrenia; Dual Diagnosis; Substance Abuse; Cannabis Abuse

Outcome Measures

Primary Outcomes (1)

• Average Over Time of Intensity of Cannabis Use (Used to Evaluate Treatment Efficacy)

  Intensity of cannabis use is obtained for each week retrospectively as the number of joints smoked during the prior week (assessed by the Timeline Followback Scale). 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.

  Week 1 to week 12

Study Arms (2)

Clozapine

EXPERIMENTAL

Clozapine, Clozaril

Drug: Clozapine

Treatment as usual

ACTIVE COMPARATOR

Treatment as usual with any antipsychotic other than Clozapine.

Drug: Treatment as usual

Interventions

Clozapine DRUG

Clozapine up to 550mg per day

Also known as: Clozaril

Clozapine

Treatment as usual DRUG

Remain on pre-study antipsychotic treatment

Treatment as usual

Eligibility Criteria

• Age: 18 Years - 65 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Meets Diagnostic and Statical Manual of Mental Disorders IV (DSM-IV) diagnostic criteria for schizophrenia or schizoaffective disorder
• Meets diagnostic criteria for marijuana use disorder, as determined by a rating of 3 or higher on the Drug Use Scale (Abuse or Dependence)
• Used marijuana on 5 or more days during the 3 weeks prior to study entry
• Taking any oral antipsychotic other than clozapine in the month prior to study entry. (Patients may take a second oral antipsychotic medication, if approved by the Medication Adjustment Group)
• If female, willing to use effective contraception throughout the study

You may not qualify if:

• Unable to take clozapine for medical reasons, including previous clozapine-induced granulocytopenia, myeloproliferative disorder, white blood cell count less than 3500/mm3, or history of seizures
• Currently taking clozapine
• Currently taking other psychotropic medications for the treatment of substance use (e.g., disulfiram, naltrexone, acamprosate, inderol, tegretol, topiramate, and pramipexole)
• Participated in a clinical trial of an investigational drug within 30 days of study entry
• Currently participating in a psychosocial intervention clinical trial
• Has medical or legal problems that may entail a jail or hospital stay during the study
• Has a developmental disability that would make study participation difficult
• Currently enrolled in a live-in treatment program for substance use disorders
• Pregnant or plans to become pregnant during the study

Sponsors & Collaborators

• Dartmouth-Hitchcock Medical Center: lead
• National Institute on Drug Abuse (NIDA): collaborator
• University of Missouri, Kansas City: collaborator
• VA Medical Center-West Los Angeles: collaborator
• University of South Carolina: collaborator

Study Sites (4)

West LA VAHCS

Los Angeles, California, 90073, United States

Location

University Missouri

Kansas City, Missouri, 64108, United States

Location

Mental Health Center of Greater Manchester

Manchester, New Hampshire, 03101, United States

Location

University South Carolina

Columbia, South Carolina, 29203, United States

Location

MeSH Terms

Conditions

Schizophrenia; Psychotic Disorders; Marijuana Abuse; Substance-Related Disorders

Interventions

Clozapine; Therapeutics

Condition Hierarchy (Ancestors)

Schizophrenia Spectrum and Other Psychotic Disorders; Mental Disorders; Chemically-Induced Disorders

Intervention Hierarchy (Ancestors)

Dibenzazepines; Heterocyclic Compounds, 3-Ring; Heterocyclic Compounds, Fused-Ring; Heterocyclic Compounds

Results Point of Contact

• Title: Christopher OKeefe
• Organization: Dartmouth Medical School

chris.okeefe@hitchcock.org

603-271-5287

Study Officials

• Alan Green, MD

  Dartmouth-Hitchcock Medical Center

  PRINCIPAL INVESTIGATOR

Publication Agreements

• PI is Sponsor Employee: No
• Restrictive Agreement: No

Study Design

• Study Type: interventional
• Phase: phase 4
• Allocation: RANDOMIZED
• Masking: SINGLE
• Who Masked: OUTCOMES ASSESSOR
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Principal Investigator

Study Record Dates

• First Submitted: July 6, 2007
• First Posted: July 10, 2007
• Study Start: October 1, 2000
• Primary Completion: March 1, 2009
• Study Completion: March 1, 2009
• Last Updated: March 13, 2019
• Results First Posted: January 19, 2012

Record last verified: 2019-02

Locations

US (4)