Analgesic and Quality of Life Effects of 1:1 Delta-9Tetrahydrocannabinol: Cannabidiol Oral Formulation on Chronic Neuropathic Pain Subjects During a Four-Week Observation Period: Pilot Study

Neuropathic pain, a chronic condition resulting from dysfunction of the central and/or peripheral nervous system(s), is often resistant to pharmacologic treatment such as gabapentin, antidepressants, and opioids; these drugs provide only limited relief and produce many intolerable adverse effects, e.g., drowsiness. Cannabinoids, including delta-9-tetrahydrocannabinol (THC) and cannabidiol (CBD), interact with the biologic endocannabinoid system to modulate nociceptive transmission and inflammation, suggesting potential benefit for neuropathic pain management. Marijuana remains a Schedule I drug which precludes conducting a standard clinical trial; thus it needs to be observational, i.e., subjects can select their doses from several options. This pilot study examines the analgesic and psychosocial effects of a balanced 1:1 THC:CBD capsule formulation taken daily at bedtime for four weeks by adults having chronic neuropathic pain lasting two months or longer. Ten subjects aged 25 to 75 years, certified under Pennsylvania’s Medical Marijuana program, have been enrolled to date. Most participants (5) selected 2.5 milligrams daily with weekly titration to 5 mg, then 10 mg, and last to 15 milligrams. The other five subjects selected different dosage sequences. Pain intensity (0-10 numeric scale) and Health-Related Quality of Life (HrQOL) parameters were assessed at start of Week 1 and end of Week 4. Preliminary results show substantial pain reduction and improved HrQOL scores in physical and social functioning, energy/fatigue, and emotional well-being. Mild transient drowsiness was reported in one subject. These early findings indicate that a balanced cannabinoid oral formulation may provide increased analgesia and improved quality-of-life benefits for neuropathic pain patients.