Characterization of the absorption phase of marijuana smoking.
M A Huestis, A H Sampson, B J Holicky, J E Henningfield, E J Cone
Clinical pharmacology and therapeutics July 1992 DOI: 10.1038/clpt.1992.100 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Double-blind, randomized, Latin square study Peer reviewed |
|---|---|
| Sample size | 6 |
| Population | Six healthy males |
| Interventions | Marijuana cigarette (placebo 1.75% or 3.55% delta-9-tetrahydrocannabinol) |
| Dose | placebo, 1.75%, or 3.55% delta-9-tetrahydrocannabinol |
| Measures | plasma delta-9-tetrahydrocannabinol levels, drug liking scores, heart rate, diastolic blood pressure |
| Topics | Cannabis |
| Key points | Plasma delta-9-tetrahydrocannabinol rose rapidly during marijuana smoking, peaking at 9 minutes before the last puff, and behavioral and physiologic effects (increased drug liking, heart rate, and diastolic blood pressure) appeared concurrently with or within minutes of peak blood levels, contrasting with prior indications of a substantial delay between peak plasma THC and drug effects. |
Abstract
Rapid blood collection, a paced smoking protocol and timely collection of physiologic and behavioral measures were used to characterize the absorption phase of marijuana smoking. Six healthy males smoked a single marijuana cigarette (placebo, 1.75%, or 3.55% delta-9-tetrahydrocannabinol) in a double-blind, randomized, Latin square study design. Rapid blood sampling with a continuous withdrawal pump allowed simultaneous collection with concurrent physiologic and behavioral measures. Mean plasma levels of 7.0 and 18.1 ng/ml delta-9-tetrahydrocannabinol were observed after the first inhalation of a 1.75% and 3.55% delta-9-tetrahydrocannabinol cigarette, respectively. Blood levels increased rapidly and peaked at 9 minutes, before initiation of the last puff sequence at 9.8 minutes. Three of six subjects reported increases in drug "liking" scores after the first puff, and all subjects responded by the second puff of a high dose cigarette. Significant increases in heart rate and diastolic blood pressure occurred shortly after peak blood levels. Previous studies have indicated that there is a substantial time delay between peak plasma levels of delta-9-tetrahydrocannabinol and drug-induced effects. This study showed that behavioral and physiologic effects appear concurrently or within minutes after the rapid appearance of delta-9-tetrahydrocannabinol in blood during marijuana smoking.