Proof of Concept Trial of Cannabis Derivatives in Neuropathic Pain

Chronic neuropathic pain (CNP) is disabling. Research on frontline treatments for CNP, shows inconsistent outcomes and dissatisfaction among Veterans. Veterans and clinicians have shown significant interest in cannabis derivatives (THC, CBD) for neuropathic pain control, but there are no well-controlled trials guiding expectations for benefit and adverse outcomes associated with cannabis for CNP. Because Veterans are likely to present with pain and pain-related polymorbidity significantly differing from that of civilians, a well-structured clinical trial of cannabinoids for Veterans with CNP is vital.

Chronic pain is a significant burden to United States Veterans and is a particular concern for Veterans. One of the causes of pain is chronic neuropathic pain (CNP). Frontline treatment for CNP, show inconsistent outcomes and have significant side effects. The ongoing opioid crisis has led to significant interest in safe and effective alternatives for pain control, and there is a significant need for research on desirable options for pain control that are likely to improve treatment adherence and outcomes. Veterans groups and Veterans Affairs clinicians have expressed significant interest in cannabis and its principal constituents (delta-9-tetrahydrocannabinol, THC; cannabidiol, CBD) for pain management, but the extant research describing the potential risks and benefits of cannabis for pain is weak. This randomized trial was developed as a proof of concept study to determine if cannabis constituents (THC, CBD, and THC+CBD) are superior to placebo in reducing pain in Veterans with CNP. The study is to recruit a sample of 320 adult Veterans who meet diagnostic criteria for high-impact CNP, are on stable treatment(s) for CNP, are not current cannabis users and who do not meet diagnostic criteria for Cannabis Use Disorder. This randomized phase II, 4-arm clinical trial aims to determine if cannabis constituents (THC, CBD) or their combination (THC+CBD) are superior to placebo in reducing pain in Veterans with CNP. This trial will offer the first evidence describing the potential benefits and adverse effects of cannabinoids for CNP in Veterans.