Short-Term Improvement in Chronic Pain for Oral Cannabinoids

Oral synthetic cannabinoid products with high tetrahydrocannabinol (THC)-to-cannabidiol (CBD) ratios are associated with moderate short-term improvement in chronic pain, according to a review published online June 7 in the Annals of Internal Medicine.

Marian S. McDonagh, Pharm.D., from the Pacific Northwest Evidence-based Practice Center in Portland, Oregon, and colleagues conducted a systematic review to assess the benefits and harms of cannabinoids for chronic pain. Data were included for 18 randomized, placebo-controlled trials with 1,740 participants and seven cohort studies with 13,095 participants.

The researchers found that there may be associations for synthetic products with high THC-to-CBD ratios (>98 percent THC) with moderate improvement in pain severity and response and increased risk for sedation, and probable associations are seen with a large increased risk of dizziness. Due to adverse events and dizziness, extracted products with high THC-to-CBD ratios may be associated with large increased risk for study withdrawal. There was a probable association for sublingual spray with comparable THC-to-CBD ratio with small improvement in pain severity and overall function, while there may be an association for a large increased risk of dizziness and sedation and moderately increased risk for nausea. Evidence was not reported or was insufficient for other products and outcomes, including longer-term harms.

“Faced with this continued deficiency of clinical evidence, some physicians cite lack of data as rationale for not engaging with patients who wish to use or currently use cannabis,” write the authors of an accompanying editorial. “This stance harms the trust necessary for shared, patient-centric decision making that is already hampered by the stigma associated with cannabis use.”