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Interaction between naltrexone and oral THC in heavy marijuana smokers.
Psychopharmacology (Berl). 2003 Feb; 166(1):77-85.P

Abstract

RATIONALE

Studies in non-human animals suggest that opioid antagonists block the reinforcing effects of cannabinoids.

OBJECTIVE

The present studies in humans investigated how naltrexone modulates (1) the subjective and physiological effects of oral THC in comparison to methadone, (2) the reinforcing effects of oral THC, and (3) plasma levels of oral THC.

METHODS

In study 1, marijuana smokers (n=9) received naltrexone (0, 50 mg) followed 30 min later by THC (0, 15, 30 mg) or methadone (5, 10 mg). Subjective effects, task performance, pupillary diameter, and cardiovascular parameters were measured repeatedly. In study 2a, marijuana smokers (n=23) were randomly assigned to one THC dose condition (0, 15 or 30 mg). One set of color-coded capsules containing THC and active naltrexone (50 mg) was given in one session, while another set of color-coded capsules containing THC and placebo naltrexone was given in another session. In the final three sessions, participants chose which color capsules they would receive. In study 2b, a subset of participants from study 2a (n=7) received naltrexone (0, 50 mg) 30 min prior to oral THC (30 mg) administration, and blood was drawn repeatedly.

RESULTS

Pretreatment with naltrexone significantly increased many of the "positive" subjective effects of oral THC (30 mg) e.g. ratings of Good Drug Effect and Capsule Liking. Naltrexone tended to increase the reinforcing effects of oral THC (30 mg), as indicated by performance in a drug choice test. Naltrexone did not alter plasma THC levels.

CONCLUSIONS

These studies demonstrate that naltrexone increases the subjective effects of oral THC. Thus, oral THC's effects are enhanced rather than antagonized by opioid receptor blockade in heavy marijuana smokers.

Authors+Show Affiliations

New York State Psychiatric Institute, College of Physicians and Surgeons of Columbia University, 1051 Riverside Drive, Unit 120, New York, NY 10032, USA. mh235@columbia.eduNo affiliation info availableNo affiliation info available

Pub Type(s)

Clinical Trial
Comparative Study
Journal Article
Randomized Controlled Trial
Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, P.H.S.

Language

eng

PubMed ID

12491025

Citation

Haney, Margaret, et al. "Interaction Between Naltrexone and Oral THC in Heavy Marijuana Smokers." Psychopharmacology, vol. 166, no. 1, 2003, pp. 77-85.
Haney M, Bisaga A, Foltin RW. Interaction between naltrexone and oral THC in heavy marijuana smokers. Psychopharmacology (Berl). 2003;166(1):77-85.
Haney, M., Bisaga, A., & Foltin, R. W. (2003). Interaction between naltrexone and oral THC in heavy marijuana smokers. Psychopharmacology, 166(1), 77-85.
Haney M, Bisaga A, Foltin RW. Interaction Between Naltrexone and Oral THC in Heavy Marijuana Smokers. Psychopharmacology (Berl). 2003;166(1):77-85. PubMed PMID: 12491025.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Interaction between naltrexone and oral THC in heavy marijuana smokers. AU - Haney,Margaret, AU - Bisaga,Adam, AU - Foltin,Richard W, Y1 - 2002/12/19/ PY - 2002/05/23/received PY - 2002/09/11/accepted PY - 2002/12/20/pubmed PY - 2003/4/19/medline PY - 2002/12/20/entrez SP - 77 EP - 85 JF - Psychopharmacology JO - Psychopharmacology (Berl) VL - 166 IS - 1 N2 - RATIONALE: Studies in non-human animals suggest that opioid antagonists block the reinforcing effects of cannabinoids. OBJECTIVE: The present studies in humans investigated how naltrexone modulates (1) the subjective and physiological effects of oral THC in comparison to methadone, (2) the reinforcing effects of oral THC, and (3) plasma levels of oral THC. METHODS: In study 1, marijuana smokers (n=9) received naltrexone (0, 50 mg) followed 30 min later by THC (0, 15, 30 mg) or methadone (5, 10 mg). Subjective effects, task performance, pupillary diameter, and cardiovascular parameters were measured repeatedly. In study 2a, marijuana smokers (n=23) were randomly assigned to one THC dose condition (0, 15 or 30 mg). One set of color-coded capsules containing THC and active naltrexone (50 mg) was given in one session, while another set of color-coded capsules containing THC and placebo naltrexone was given in another session. In the final three sessions, participants chose which color capsules they would receive. In study 2b, a subset of participants from study 2a (n=7) received naltrexone (0, 50 mg) 30 min prior to oral THC (30 mg) administration, and blood was drawn repeatedly. RESULTS: Pretreatment with naltrexone significantly increased many of the "positive" subjective effects of oral THC (30 mg) e.g. ratings of Good Drug Effect and Capsule Liking. Naltrexone tended to increase the reinforcing effects of oral THC (30 mg), as indicated by performance in a drug choice test. Naltrexone did not alter plasma THC levels. CONCLUSIONS: These studies demonstrate that naltrexone increases the subjective effects of oral THC. Thus, oral THC's effects are enhanced rather than antagonized by opioid receptor blockade in heavy marijuana smokers. SN - 0033-3158 UR - https://www.unboundmedicine.com/medline/citation/12491025/Interaction_between_naltrexone_and_oral_THC_in_heavy_marijuana_smokers_ L2 - https://dx.doi.org/10.1007/s00213-002-1279-8 DB - PRIME DP - Unbound Medicine ER -