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Key Points Question Is inhaled cannabis with an approximately 1:1 ratio of Δ-9-tetrahydrocannabinol to cannabidiol a safe and effective adjunct to opioids in adults with sickle cell disease–related pain? Findings This randomized clinical trial including 23 participants found that inhaled cannabis was safe. Inhaled cannabis was more effective than inhaled placebo in interference in mood, but there was no statistically significant difference in pain rating between cannabis and placebo. Meaning These findings suggest that cannabis should be investigated further in larger and longer clinical trials in adults with sickle cell disease with chronic pain as an adjunct or alternative to opioids., This randomized clinical trial examines the safety and efficacy of cannabis for pain in adults with sickle cell disease., 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: 0.27 [0.35]; day 5: −1.0 [0.5]), walking (day 1: 0.14 [0.73]; day 5: −0.87 [0.63]), sleep (day 1: 0.59 [0.74]; day 5: −1.3 [0.8]), or enjoyment (day 1: 0.23 [0.69]; day 5: −0.91 [0.48]), but there was a statistically significant mean (SD) difference in decrease in interference with mood (day 1: 0.96 [0.59]; day 5: −1.4 [0.6]; P = .02). No differences in treatment-related adverse effects were observed. Use of concomitant opioids was similar during both treatment periods. Conclusions and Relevance This randomized clinical trial found that, compared with vaporized placebo, vaporized cannabis did not statistically significantly reduce pain and associated symptoms, except interference in mood, in patients with SCD with chronic pain. Trial Registration ClinicalTrials.gov Identifier: NCT01771731

The sickle hemoglobin is an abnormal hemoglobin due to point mutation (GAG → GTG) in exon 1 of the β globin gene resulting in the substitution of glutamic acid by valine at position 6 of the β globin polypeptide chain. Although the molecular lesion is a single-point mutation, the sickle gene is pleiotropic in nature causing multiple phenotypic expressions that constitute the various complications of sickle cell disease in general and sickle cell anemia in particular. The disease itself is chronic in nature but many of its complications are acute such as the recurrent acute painful crises (its hallmark), acute chest syndrome, and priapism. These complications vary considerably among patients, in the same patient with time, among countries and with age and sex. To date, there is no well-established consensus among providers on the management of the complications of sickle cell disease due in part to lack of evidence and in part to differences in the experience of providers. It is the aim of this paper to review available current approaches to manage the major complications of sickle cell disease. We hope that this will establish another preliminary forum among providers that may eventually lead the way to better outcomes.