DIalysis Symptom COntrol-Pruritus Outcome Trial (DISCO-POT): A Multicenter Randomized Blinded Placebo Controlled Crossover Trial

Rationale & Objective Uremic pruritus affects up to 50% of patients with kidney failure and negatively impacts quality of life. Itch often persists and remains insufficiently controlled despite standard of care treatments. We evaluated the effects of nabilone, a synthetic cannabinoid, in patients with kidney failure receiving dialysis and symptoms of chronic itch. Study Design Placebo controlled randomized crossover trial. Setting & Participants Adults >25 years old receiving maintenance hemodialysis at least 2x weekly or peritoneal dialysis daily with at least moderate itch. Interventions Participants were randomly allocated to a first treatment period of either oral nabilone (0.5mg daily for 1 week then twice a day for 3 weeks) or an identical placebo regimen. After a 2-week washout period, participants received whichever regimen they did not receive in the first treatment period. Outcomes The primary outcome was the difference in worst visual analog score (0 to 100mm) for itch over the last 24 hours in each treatment period. Results Of 14 participants randomized, all were on hemodialysis The worst visual analog score for the nabilone compared to the placebo was 4.88mm (95% CI -3.61 to 13.38, p=0.28), indicating worse itch with nabilone. The study was not able to detect any differences in nabilone from placebo in other measures of itch, sleep, quality of life or adverse events but was short in duration study and had a limited sample. Limitations Underpowered for secondary outcomes and to detect carryover effects, conservative nabilone dosing. Conclusions We were unable to detect if nabilone had any effects on uremic pruritus compared to placebo. Plain-Language Summary Uremic pruritus, also known as chronic itch that is associated with kidney disease, affects up to half of patients on dialysis and is associated with worse quality of life. Unfortunately, few effective and well-tolerated treatments exist for this troublesome symptom. Nabilone, a synthetic form of tetrahydrocannbinol (THC), is a potential new treatment for uremic pruritus, given the possible role of cannabinoid receptors in chronic itch. In this small crossover trial in which adults receiving maintenance dialysis each received nabilone and placebo in a random order for 4 weeks, we did not detect any differences in itch severity, sleep or quality of life between the two treatments but nabilone was well-tolerated without any significant side effects.