Effects of Low-dose Naltrexone in Combination With a Range of Smoked Marijuana

Phase 2

Completed

• Conditions: Marijuana Smoking
• Interventions: Drug: Active Marijuana (5.5% THC); Drug: Active Marijuana (6.2% THC); Drug: Inactive Marijuana (0% THC); Drug: Placebo naltrexone; Drug: Naltrexone

• Registration Number: NCT00743145
• Lead Sponsor: New York State Psychiatric Institute

Brief Summary

In heavy marijuana smokers, opioid receptor blockade increases the subjective and cardiovascular effects of marijuana. The current study was designed to clarify opioid-cannabinoid interactions by assessing how naltrexone shifts the dose-response function for marijuana-elicited effects in heavy marijuana smokers. For this within-subject, double-blind study, a marijuana smoking procedure was designed to characterize a dose-response relationship for marijuana's subjective and cardiovascular effects under blinded conditions.

Detailed Description

Not available

Study Timeline

• Study Start: 2008-05
• Study First Submitted: 2008-08-26
• Study First Submitted QC: 2008-08-26
• Study First Posted: 2008-08-28
• Primary Completion: 2009-07
• Study Completion: 2009-09
• Results First Submitted: 2017-08-14
• Status Verified: 2018-08
• Results First Submitted QC: 2018-08-16
• Last Update Submitted: 2018-08-16
• Results First Posted: 2018-09-14
• Last Update Posted: 2018-09-14

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 23

Inclusion Criteria

• Current marijuana use
• Able to perform study procedures
• Women practicing an effective form of birth control

Exclusion Criteria

• Current repeated illicit drug use (other than marijuana)
• Presence of significant medical illness (e.g., diabetes, cardiovascular disease,hypertension, hepatitis, clinically significant laboratory abnormalities, LFTs > 3x upper limit of normal, blood pressure > 140/90

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: CROSSOVER

Arm && Interventions

Group	Intervention	Description
Placebo naltrexone + Active marijuana (5.5% THC)	Active Marijuana (5.5% THC)	Placebo naltrexone capsules (0mg), active marijuana (5.5% THC). Each study participant underwent 8 conditions in a randomized order.
Placebo naltrexone + Active marijuana (6.2% THC)	Active Marijuana (6.2% THC)	Placebo naltrexone capsules (0mg), active marijuana (6.2% THC). Each study participant underwent 8 conditions in a randomized order.
Placebo naltrexone + Inactive marijuana	Inactive Marijuana (0% THC)	Placebo naltrexone capsules (0mg), inactive marijuana (0% THC). Each study participant underwent 8 conditions in a randomized order.
Placebo naltrexone + Active marijuana (6.2% THC)	Placebo naltrexone	Placebo naltrexone capsules (0mg), active marijuana (6.2% THC). Each study participant underwent 8 conditions in a randomized order.
Placebo naltrexone + Inactive marijuana	Placebo naltrexone	Placebo naltrexone capsules (0mg), inactive marijuana (0% THC). Each study participant underwent 8 conditions in a randomized order.
Naltrexone + Active marijuana (5.5% THC)	Active Marijuana (5.5% THC)	Naltrexone capsules (12mg), active marijuana (5.5% THC). Each study participant underwent 8 conditions in a randomized order.
Placebo naltrexone + Active marijuana (5.5% THC)	Placebo naltrexone	Placebo naltrexone capsules (0mg), active marijuana (5.5% THC). Each study participant underwent 8 conditions in a randomized order.
Naltrexone + Active marijuana (6.2% THC)	Active Marijuana (6.2% THC)	Naltrexone capsules (0mg), active marijuana (6.2% THC). Each study participant underwent 8 conditions in a randomized order.
Naltrexone + Inactive marijuana	Inactive Marijuana (0% THC)	Naltrexone capsules (12mg), inactive marijuana (0% THC). Each study participant underwent 8 conditions in a randomized order.
Naltrexone + Active marijuana (5.5% THC)	Naltrexone	Naltrexone capsules (12mg), active marijuana (5.5% THC). Each study participant underwent 8 conditions in a randomized order.
Naltrexone + Inactive marijuana	Naltrexone	Naltrexone capsules (12mg), inactive marijuana (0% THC). Each study participant underwent 8 conditions in a randomized order.
Naltrexone + Active marijuana (6.2% THC)	Naltrexone	Naltrexone capsules (0mg), active marijuana (6.2% THC). Each study participant underwent 8 conditions in a randomized order.

Primary Outcome Measures

Name	Time	Method
Subjective Marijuana Effects	180 minutes after marijuana administration, during each of 8 outpatient sessions over the course of 3-6 weeks.	Subjective ratings of marijuana's quality and effect ('Strength', 'Good Effect', 'High', 'Stimulation') and craving ('Want Marijuana') as a function of active puffs and naltrexone, using a visual analogue scale with a series of 100 mm long lines labeled 'not at all' at one end (0 mm) and 'extremely' at the other end (100 mm). Participants were instructed to indicate how they felt at that particular moment. Higher ratings indicate more agreement with the statement.

Trial Locations

Locations (1)

New York State Psychiatric Institute; 🇺🇸 New York, New York, United States