Comparison of smoked marijuana and oral Delta(9)-tetrahydrocannabinol in humans.
BACKGROUND
Although smoked marijuana contains at least 60 cannabinoids, delta(9)-tetrahydrocannabinol (delta(9)-THC) is presumed to be the cannabinoid primarily responsible for many marijuana-related effects, including increased food intake and subjective effects. Yet, there has been no systematic comparison of repeated doses of oral delta(9)-THC with repeated doses of smoked marijuana in the same individuals.


OBJECTIVE
To compare the effects of oral delta(9)-THC and smoked marijuana in humans under controlled laboratory conditions.


METHODS
Eleven healthy research volunteers, who reported smoking an average of six marijuana cigarettes per day, completed an 18-day residential study. Marijuana cigarettes (3.1% delta(9)-THC, q.i.d.) were smoked or delta(9)-THC (20 mg, q.i.d.) was taken orally using a staggered, double-blind, double-dummy procedure for three consecutive days. Four days of placebo administration separated each active drug condition. Psychomotor task performance, subjective effects, and food intake were measured throughout the day.


RESULTS
Relative to placebo baseline, oral delta(9)-THC and smoked marijuana produced similar subjective-effect ratings (e.g., "high" and "mellow"), although some effects of smoked marijuana were more pronounced and less prone to the development of tolerance. Additionally, participants reported "negative" subjective effects (e.g., "irritable" and "miserable") during the days after smoking marijuana but not after oral delta(9)-THC. Both drugs increased food intake for 3 days of drug administration, but had little effect on psychomotor performance.


CONCLUSIONS
These results indicate that the behavioral profile of effects of smoked marijuana (3.1% delta(9)-THC) is similar to the effects of oral delta(9)-THC (20 mg), with some subtle differences.
Hart
Carl L
CL
Division on Substance Abuse, New York State Psychiatric Institute, New York, NY 10032, USA. clh42@columbia.edu
Ward
Amie S
AS
Haney
Margaret
M
Comer
Sandra D
SD
Foltin
Richard W
RW
Fischman
Marian W
MW
D000284:Administration, Oral; D000328:Adult; D001288:Attention / Q000187:drug effects*; D004311:Double-Blind Method; D013759:Dronabinol / Q000008:administration & dosage*; D004361:Drug Tolerance; D004435:Eating / Q000187:drug effects*; D005059:Euphoria / Q000187:drug effects*; D005260:Female; D006801:Humans; D007508:Irritable Mood / Q000187:drug effects; D008297:Male; D008385:Marijuana Smoking / Q000523:psychology*; D011597:Psychomotor Performance / Q000187:drug effects*
D013759:Dronabinol