Background and objectivesThe use of cannabinoids for appetite stimulation and the management of wasting and antiretroviral side-effects has become a common practice in the care of HIV-infected individuals. We present pharmacokinetic data from a randomized placebo-controlled study designed to evaluate the metabolic effects of smoked marijuana and dronabinol in HIV-infected patients receiving indinavir (IDV) or nelfinavir (NFV).MethodsSubjects on stable regimens containing IDV 800 mg every 8 h (n = 28) or NFV 750 mg three time a day (n = 34) were randomized to one of three treatment arms: 3.95% THC marijuana cigarettes, dronabinol 2.5 mg capsules or placebo capsules administered three times daily. Serial blood sampling was performed at baseline and on day 14 of treatment. The changes in NFV and IDV pharmacokinetics were measured as the median percentage change from baseline.ResultsAt day 14, the 8-h area under the curve (AUC8) changed by −10.2% (P= 0.15), maximum concentration (Cmax) by −17.4% (P= 0.46), and minimum concentration (Cmin) by −12.2% (P= 0.28) for patients in the NFV marijuana arm (n = 11). Similar decreases had occurred by day 14 among patients in the IDV marijuana arm (n = 9): AUC8had changed by −14.5% (P= 0.074), Cmaxby −14.1% (P= 0.039), and Cminby −33.7% (P= 0.65).ConclusionDespite a statistically significant decrease in Cmaxof IDV in the marijuana arm, the magnitude of changes in IDV and NFV pharmacokinetic parameters in the marijuana arm are likely to have no short-term clinical consequence. The use of marijuana or dronabinol is unlikely to impact antiretroviral efficacy.