Delta-9-tetrahydrocannabinol delays the gastric emptying of solid food in humans: a double-blind, randomized study

Background: Delta-9-tetrahydrocannabinol (THC), the active constituent of m arijuana, is an effective agent in the prevention of chemotherapy-induced n ausea and vomiting, Aim: To determine the effect of THC on gastric emptying of a radiolabelled solid food in humans. Methods: Thirteen healthy volunteers underwent gastric emptying studies aft er receiving THC and placebo in a randomized double-blind fashion on 2 sepa rate days. THC, at a dose of 10 mg/m(2) of body surface area, or placebo we re administered. Results: Gastric emptying after THC was slower than placebo in all subjects . Mean percentage of isotope remaining in the stomach was significantly gre ater than after placebo from 30 min (85.5 +/- 4.3% vs. 94.2 +/- 1.4% placeb o and THC, respectively, P < 0.05) to 120 min (45.6 +/- 7.2% vs. 73.9 +/- 7 .1% placebo and THC, respectively, P < 0.001) after the test meal, No corre lation was found between plasma THC levels and the delay in gastric emptyin g. Conclusions: THC at a dose used for preventing chemotherapy-induced nausea and vomiting significantly delays gastric emptying of solid food in humans, Therefore, the anti-emetic property of THC may be mediated through the cen tral nervous system.