Pharmacodynamic effects of vaporized and oral cannabidiol (CBD) and vaporized CBD-dominant cannabis in infrequent cannabis users

Abstract

Introduction: The use and availability of oral and inhalable products containing cannabidiol (CBD) as the principal constituent has increased with expanded cannabis/hemp legalization. However, few controlled clinical laboratory studies have evaluated the pharmacodynamic effects of oral or vaporized CBD or CBD-dominant cannabis.

Methods: Eighteen healthy adults (9 men; 9 women) completed four, double-blind, double-dummy, drug administration sessions. Sessions were separated by ≥1 week and included self-administration of 100 mg oral CBD, 100 mg vaporized CBD, vaporized CBD-dominant cannabis (100 mg CBD; 3.7 mg THC), and placebo. Study outcomes included: subjective drug effects, vital signs, cognitive/psychomotor performance, and whole blood THC and CBD concentrations.

Results: Vaporized CBD and CBD-dominant cannabis increased ratings on several subjective items (e.g., Like Drug Effect) relative to placebo. Subjective effects did not differ between oral CBD and placebo and were generally higher for CBD-dominant cannabis compared to vaporized CBD. CBD did not increase ratings for several items typically associated with acute cannabis/THC exposure (e.g., Paranoid). Women reported qualitatively higher ratings for Pleasant Drug Effect than men after vaporized CBD and CBD-dominant cannabis use. CBD-dominant cannabis increased heart rate compared to placebo. Cognitive/psychomotor impairment was not observed in any drug condition.

Conclusions: Vaporized CBD and CBD-dominant cannabis produced discriminable subjective drug effects, which were sometimes stronger in women, but did not produce cognitive/psychomotor impairment. Subjective effects of oral CBD did not differ from placebo. Future research should further elucidate the subjective effects of various types of CBD products (e.g., inhaled, oral, topical), which appear to be distinct from THC-dominant products.

Keywords: Cannabidiol; Cannabis; Pharmacodynamics; THC; Vaporizer.

Fig. 1.

Mean ratings (+ SEM) for visual analog scale (VAS) items Pleasant Drug Effect (top panels) and Like Drug Effect (bottom panels) from the Drug Effect Questionnaire (DEQ) displayed over time for the four dosing conditions. These results are depicted for the entire sample (N = 18; far left panels), men only (N = 9; middle panels), and women only (N = 9; far right panels). Scores ranged from 0 (not at all) to 100 (extremely). Oral doses were administered at baseline (BL) time point, inhaled doses were administered at hour 1.

Fig. 2.

Mean (+ SEM) values for heart rate (in beats per minute; bpm) displayed over time for the four dosing conditions. These results are depicted for the entire sample (N = 18; far left panels), men only (N = 9; middle panels), and women only (N = 9; far right panels). Oral doses were administered at baseline (BL) time point, inhaled doses were administered at hour 1.

Fig. 3.

Mean (+ SEM) whole blood concentrations (in ng/mL) for CBD (top panels) and THC (bottom panels) displayed over time for the three active dosing conditions (i.e., 100 mg vaporized CBD; 100 mg oral CBD; CBD-dominant cannabis with 100 mg CBD and 3.7 mg THC). These results are depicted for the entire sample (N = 18; far left panels), men only (N = 9; middle panels), and women only (N = 9; far right panels). Oral doses were administered at baseline (BL) time point, inhaled doses were administered at hour 1.