Cannabis-Based Products for Chronic Pain : An Updated Systematic Review.

Area of Science:

• Pharmacology and Therapeutics
• Pain Management
• Evidence Synthesis

Background:

• The efficacy and safety of cannabinoids for managing chronic pain remain uncertain.
• Existing evidence requires updating to inform clinical practice and patient care.
• Cannabinoids are increasingly explored for their analgesic properties.

Purpose of the Study:

• To conduct an updated evidence synthesis on the benefits and harms of cannabinoids for chronic pain.
• To evaluate cannabinoids based on their THC-to-CBD ratio, source, and administration method.
• To provide a comprehensive overview of current research findings.

Main Methods:

• Systematic review of randomized placebo-controlled trials (RCTs) published up to July 2025.
• Searches conducted across major databases: Ovid MEDLINE, PsycINFO, Embase, Cochrane Library, and Scopus.
• Data extraction and risk of bias assessment performed by dual reviewers; strength of evidence evaluated.

Main Results:

• Twenty-five RCTs (n=2303) assessed short-term cannabinoid use, primarily for neuropathic pain.
• High THC-to-CBD ratio products (oral synthetic/purified or oromucosal extracted) showed slight pain reduction but increased dizziness, sedation, and nausea.
• Nabilone (high THC-only) reduced pain, while dronabinol did not; low THC-to-CBD interventions showed no significant benefit.

Conclusions:

• Certain cannabinoid products with comparable or high THC-to-CBD ratios may offer modest short-term pain relief for neuropathic pain, accompanied by common adverse events.
• Nabilone demonstrated efficacy among high THC-only products, unlike dronabinol.
• Further research is needed on long-term outcomes and diverse cannabis product types, particularly those with low THC-to-CBD ratios.