Gabapentin Treatment of Cannabis Dependence

Phase 2

Completed

Interventions: Drug: gabapentin 1200mg/day
Drug: Placebo
Behavioral: Manual-guided behavioral counseling

Brief Summary: This is a clinical study to evaluate the efficacy of the medication gabapentin in treating persons with cannabis dependence.

Detailed Description: This is a 12-week, double blind, placebo controlled study to evaluate the efficacy of gabapentin in treating outpatients with cannabis dependence. After an initial phone screen, a comprehensive screening visit is scheduled to determine eligibility. Upon enrollment, counseling, medication dispensation and research assessments occur 1 time per week for 3 months.

Recruitment & Eligibility

Inclusion Criteria

Males or females from 18-65 years of age
Meets DSM IV criteria for current cannabis dependence
Seeking research-based outpatient treatment for cannabis dependence that involves daily medication
Smoked MJ daily at least 25 days per month during the 90 days prior to randomization
At least a 2-year history of regular MJ use

Exclusion Criteria

Abstinent from cannabis more than 2 days at the time of randomization
Active suicidal ideation
Currently meets DSM IV criteria for abuse or dependence on other substances, or has urine drug screen positive for substances, other than cannabis or nicotine
Significant medical disorders that will increase potential risk or interfere with study participation,
Sexually active female participants with childbearing potential who are pregnant, nursing or refuse to use a reliable method of birth control
Meets DSM IV criteria for a major AXIS I disorder other than cannabis and nicotine dependence,
Inability to understand and/or comply with the provisions of the protocol and consent form
Treatment with an investigational drug during the previous month
Sensitivity to study drug as evidenced by adverse drug experiences with gabapentin or its ingredients
Ongoing treatment with medications that may affect study outcomes

Arm && Interventions

Group	Intervention	Description
Gabapentin 1200mg/day	gabapentin 1200mg/day	1200mg/day of gabapentin for 12 weeks given in conjunction with 12 weeks of manual-guided behavioral counseling.
Placebo	Manual-guided behavioral counseling	1200mg/day of placebo for 12 weeks given in conjunction with 12 weeks of manual-guided behavioral counseling.
Gabapentin 1200mg/day	Manual-guided behavioral counseling	1200mg/day of gabapentin for 12 weeks given in conjunction with 12 weeks of manual-guided behavioral counseling.
Placebo	Placebo	1200mg/day of placebo for 12 weeks given in conjunction with 12 weeks of manual-guided behavioral counseling.

Primary Outcome Measures

Name	Time	Method
Percentage of Negative Urinary Drug Screens (UDS) for Cannabis at 12 Weeks Following Administration of Gabapentin or Placebo During the Double Blind Period	12 weeks	Express Results Integrated Multi-Drug Screen Cups were used to obtain a semi-quantitative urine drug screen for delta-9-THC. Submitted UDS would yield a positive result when the concentration of THC-COOH in urine exceeded 50 ng/mL. Specimens were collected weekly. Two analytical approaches were used: one where any missed UDS test was assumed positive (i.e intent-to-treat (ITT)) and another where missed UDS were considered missing at random (MAR).

Secondary Outcome Measures