Short-Term Effects of Cannabinoids in Patients with HIV-1 Infection

Background: Cannabinoid use could potentially alter HIV RNA levels by two mechanisms: immune modulation or cannabinoid– protease inhibitor interactions (because both share cytochrome P-450 metabolic pathways).

Objective: To determine the short-term effects of smoked marijuana on the viral load in HIV-infected patients. Design: Randomized, placebo-controlled, 21-day intervention trial. Setting: The inpatient General Clinical Research Center at the San Francisco General Hospital, San Francisco, California. Participants: 67 patients with HIV-1 infection.

Intervention: Participants were randomly assigned to a 3.95%- tetrahydrocannabinol marijuana cigarette, a 2.5-mg dronabinol (delta-9-tetrahydrocannabinol) capsule, or a placebo capsule three times daily before meals.

Measurements: HIV RNA levels, CD4 and CD8 cell subsets, and pharmacokinetic analyses of the protease inhibitors.

Results: 62 study participants were eligible for the primary end point (marijuana group, 20 patients; dronabinol group, 22 patients; and placebo group, 20 patients). Baseline HIV RNA level was less than 50 copies/mL for 36 participants (58%), and the median CD4 cell count was 340 109 cells/L. When adjusted for baseline variables, the estimated average effect versus placebo on change in log10 viral load from baseline to day 21 was 0.07 (95% CI, 0.30 to 0.13) for marijuana and 0.04 (CI, 0.20 to 0.14) for dronabinol. The adjusted average changes in viral load in marijuana and dronabinol relative to placebo were 15% (CI, 50% to 34%) and 8% (CI, 37% to 37%), respectively. Neither CD4 nor CD8 cell counts appeared to be adversely affected by the cannabinoids.

Conclusions: Smoked and oral cannabinoids did not seem to be unsafe in people with HIV infection with respect to HIV RNA levels, CD4 and CD8 cell counts, or protease inhibitor levels over a 21-day treatment.