A recent randomized, double blind, parallel group study investigated whether subacute (2-week) treatment with the CB1 receptor antagonist rimonabant (40 mg daily) attenuated the effects of smoked cannabis in 42 healthy men with a history of cannabis use [54]. The repeated daily rimonabant doses attenuated the acute cardiovascular effects of a cannabis cigarette (2.78% THC) to a similar degree as a single 90-mg dose; repeated 40-mg doses attenuated subjective effects after 8 but not 15 days (possibly because of smaller sample size and lower statistical power at day 15). Rimonabant did not significantly affect THC pharmacokinetics, suggesting that the observed effects were due to receptor blockade and not reduced THC levels in the brain.
