Cannabidivarin for the treatment of HIV-associated neuropathic pain: a randomized, blinded, controlled clinical trial

Background: HIV remains a major burden to the health care system and neuropathic pain is the most common neurological complication of HIV-infection. Since current treatment strategies often lack satisfying pain relief, cannabinoids are discussed as a new option. We investigated Cannabidivarin as treatment for HIV-associated neuropathic pain. Methods: We conducted a randomized, double-blind, placebo-controlled cross-over study. Patients underwent two successive treatment phases (4 weeks each) and were treated with Cannabidivarin (400mg/d) or placebo in a randomized order. A 3-week wash-out phase was designed to eliminate potential carry-overeffects and patients were followed up for 3 weeks after the end of the second treatment phase. The primary endpoint was pain intensity on an 11-point numeric rating scale and was recorded in a diary. Secondary endpoints were additional pain medication, pain characteristics and quality of life. Results: We included 32 (31 male) patients. The mean pain intensity under Cannabidivarin was by 0.62 points higher compared to placebo (p=0.16; 95% CI -0.27 to 1.51). Cannabidivarin did not influence the amount of additional pain medication, pain characteristics or quality of life. No suspected unexpected adverse reactions occurred during the trial. Discussion: Cannabidivarin was safe but failed to reduce neuropathic pain intensity in HIV-patients. This may be explained by a lack of cannabinoid receptor activation, as indicated by preclinical experiments. Further studies on larger sample sizes are needed.