NCT00403117

Effects of a Range of Naltrexone Doses in Combination With Smoked Marijuana

Opioid Antagonism Enhances Marijuana's Effects in Heavy Marijuana Smokers

• Status: Completed
• Phase: Phase 2
• Study type: Interventional
• Enrollment: 49 (actual)
• Sponsor: New York State Psychiatric Institute · Academic / Other
• Sex: All
• Age: 21 Years – 45 Years
• Healthy volunteers: Accepted

Summary

The purpose of this study is to determine if the subjective effects of marijuana will be decreased by low-doses (\< 25 mg) of naltrexone and increased by high-doses (\> 50 mg) of naltrexone.

Detailed description

Laboratory animal studies demonstrate that endogenous cannabinoids and opioids are closely inter-related. We have completed a series of studies in marijuana smokers showing that a clinically-utilized dose of naltrexone (50 mg) enhanced the reinforcing and subjective effects of orally-administered tetrahydrocannabinol (THC), while a low naltrexone dose (12 mg) blunted the effects of THC. A better understanding of the effects of a range of naltrexone doses in combination with smoked marijuana has important implications for the following reasons: (1) Alcohol- and opioid-dependent patients receive high doses of naltrexone (50-150 mg), which may increase the abuse liability of marijuana, (2) Low-dose naltrexone blunts THC's intoxicating effects, suggesting potential utility as a treatment medication for marijuana dependence. This study will determine if naltrexone (0, 12, 25, 50, 100 mg) administration 45 min prior to marijuana administration (0, 3.27% THC) alters marijuana's subjective, cognitive or physiological effects. Marijuana smokers will spend approximately 5h/day for a total of 10 days in the outpatient laboratory. Participants will visit the outpatient laboratory 2-3 times per week, with a minimum 48-hr interval between sessions to allow for naltrexone clearance. These data will provide important information regarding the clinical use of naltrexone.

Conditions

• Marijuana Use

Interventions

Type	Name	Description
DRUG	Placebo + Inactive Marijuana (0% THC)	One capsule containing placebo was administered to the participant in a size 00 opaque capsules with lactose filler 45 minutes before marijuana administration.
DRUG	Placebo + Active Marijuana (3.27% THC)	One capsule containing placebo was administered to the participant in a size 00 opaque capsules with lactose filler 45 minutes before administration of a marijuana cigarette containing 3.27% THC (ca. 800 mg) provided by the National Institute on Drug Abuse.
DRUG	Naltrexone 12 Mg+ Active Marijuana (3.27% THC)	One capsule containing 12mg Naltrexone was administered to the participant in a size 00 opaque capsules with lactose filler 45 minutes before active marijuana administration.
DRUG	Naltrexone 25 Mg + Active Marijuana (3.27% THC)	One capsule containing 12mg Naltrexone was administered to the participant in a size 00 opaque capsules with lactose filler 45 minutes before active marijuana administration.
DRUG	Naltrexone 50 Mg+ Active Marijuana (3.27% THC)	One capsule containing 25mg Naltrexone was administered to the participant in a size 00 opaque capsules with lactose filler 45 minutes before marijuana administration.
DRUG	Naltrexone 100 Mg+ Active Marijuana (3.27% THC)	One capsule containing 50mg Naltrexone was administered to the participant in a size 00 opaque capsules with lactose filler 45 minutes before marijuana administration.
DRUG	Naltrexone 12 Mg + Inactive Marijuana (0% THC)	One capsule containing 12mg Naltrexone was administered to the participant in a size 00 opaque capsules with lactose filler 45 minutes before inactive marijuana administration.
DRUG	Naltrexone 25 Mg + Inactive Marijuana (0% THC)	One capsule containing 25mg Naltrexone was administered to the participant in a size 00 opaque capsules with lactose filler 45 minutes before inactive marijuana administration.
DRUG	Naltrexone 50 Mg + Inactive Marijuana (0% THC)	One capsule containing 50mg Naltrexone was administered to the participant in a size 00 opaque capsules with lactose filler 45 minutes before inactive marijuana administration.
DRUG	Naltrexone 100 Mg + Inactive Marijuana (0% THC)	One capsule containing 100mg Naltrexone was administered to the participant in a size 00 opaque capsules with lactose filler 45 minutes before inactive marijuana administration.

Timeline

• Start date: 2006-12-01
• Primary completion: 2008-05-01
• Completion: 2010-08-01
• First posted: 2006-11-23
• Last updated: 2018-03-15
• Results posted: 2017-12-19

Regulatory

• FDA-regulated drug study