Cannabinoids and opioids share several pharmacologic properties and may act synergistically. The potential pharmacokinetics and the safety of the combination in humans are unknown. We therefore undertook a study to answer these questions. Twenty-one individuals with chronic pain, on a regimen of twice-daily doses of sustained-release morphine or oxycodone were enrolled in the study and admitted for a 5-day inpatient stay. Participants were asked to inhale vaporized cannabis in the evening of day 1, three times a day on days 2-4, and in the morning of day 5. Blood sampling was performed at 12-h intervals on days 1 and 5. The extent of chronic pain was also assessed daily. Pharmacokinetic investigations revealed no significant change in the area under the plasma concentration-time curves for either morphine or oxycodone after exposure to cannabis. Pain was significantly decreased (average 27%, 95% confidence interval (CI) 9, 46) after the addition of vaporized cannabis. We therefore concluded that vaporized cannabis augments the analgesic effects of opioids without significantly altering plasma opioid levels. The combination may allow for opioid treatment at lower doses with fewer side effects.

IMPORTANCE Sickle cell disease (SCD) is characterized by chronic pain and episodic acute pain caused by vasoocclusive crises, often requiring high doses of opioids for prolonged periods. In humanized mouse models of SCD, a synthetic cannabinoid has been found to attenuate both chronic and acute hyperalgesia. The effect of cannabis on chronic pain in adults with SCD is unknown. OBJECTIVE To determine whether inhaled cannabis is more effective than inhaled placebo in relieving chronic pain in adults with SCD. DESIGN, SETTING, AND PARTICIPANTS This pilot randomized clinical trial included participants with SCD with chronic pain admitted to a single inpatient clinical research center for 2 separate 5-day stays from August 2014 to April 2017. Participants inhaled either vaporized cannabis (4.4% Δ-9-tetrahydrocannabinol to 4.9% cannabidiol) 3 times daily or vaporized placebo cannabis. Pain and pain interference ratings using the Brief Pain Inventory were assessed throughout each 5-day period. Participants with SCD and chronic pain on stable analgesics were eligible to enroll. A total of 90 participants were assessed for eligibility; 56 participants were deemed ineligible, and 34 participants were enrolled. Of these, 7 participants dropped out before randomization. Of 27 randomized participants, 23 completed both treatment arms of the crossover study and were included in the final per protocol analysis. Data analysis was completed in June 2019, with the sensitivity analysis conducted in April 2020. INTERVENTIONS Inhalation of vaporized cannabis plant (4.4% Δ-9-tetrahydrocannbinol to 4.9% cannabidiol) or placebo cannabis plant using a vaporizer 3 times daily for 5 days. MAIN OUTCOMES AND MEASURES Daily pain assessed with visual analog scale and Brief Pain Inventory. RESULTS A total of 23 participants (mean [SD] age, 37.6 [11.4] years; 13 [56%] women) completed the trial. The mean (SD) difference in pain rating assessment between the cannabis and placebo groups was −5.3 (8.1) for day 1, −10.9 (7.0) for day 2, −16.5 (9.2) for day 3, −8.9 (6.7) for day 4, and −8.2 (8.1) for day 5; however, none of these differences were statistically significant. There was no statistically significant mean (SD) difference in pain interference ratings between cannabis and placebo between days 1 and 5 for interference in general activities (day 1: 0.

IntroductionThe use of anti-retroviral therapy (ART) has dramatically reduced HIV-1 associated morbidity and mortality. However, HIV-1 infected individuals have increased rates of morbidity and mortality compared to the non-HIV-1 infected population and this appears to be related to end-organ diseases collectively referred to as Serious Non-AIDS Events (SNAEs). Circulating miRNAs are reported as promising biomarkers for a number of human disease conditions including those that constitute SNAEs. Our study sought to investigate the potential of selected miRNAs in predicting mortality in HIV-1 infected ART treated individuals.Materials and MethodsA set of miRNAs was chosen based on published associations with human disease conditions that constitute SNAEs. This case: control study compared 126 cases (individuals who died whilst on therapy), and 247 matched controls (individuals who remained alive). Cases and controls were ART treated participants of two pivotal HIV-1 trials. The relative abundance of each miRNA in serum was measured, by RTqPCR. Associations with mortality (all-cause, cardiovascular and malignancy) were assessed by logistic regression analysis. Correlations between miRNAs and CD4+ T cell count, hs-CRP, IL-6 and D-dimer were also assessed.ResultsNone of the selected miRNAs was associated with all-cause, cardiovascular or malignancy mortality. The levels of three miRNAs (miRs -21, -122 and -200a) correlated with IL-6 while miR-21 also correlated with D-dimer. Additionally, the abundance of miRs -31, -150 and -223, correlated with baseline CD4+ T cell count while the same three miRNAs plus miR-145 correlated with nadir CD4+ T cell count.DiscussionNo associations with mortality were found with any circulating miRNA studied. These results cast doubt onto the effectiveness of circulating miRNA as early predictors of mortality or the major underlying diseases that contribute to mortality in participants treated for HIV-1 infection.