THERAPEUTIC CANNABIS AND OPIOID REDUCTION IN CHRONIC PAIN: CURRENT EVIDENCE AND CLINICAL PERSPECTIVES

I. Olivieri, G. Di Giuseppe, C. Angeletti | Anestesia, Rianimazione, Terapia del dolore, Ospedale G. Mazzini, Teramo, Italy

Introduction. Chronic pain is a major clinical burden and remains a common reason for long-term opioid therapy. Although opioids may provide analgesic benefit, their prolonged use is limited by tolerance, dependence, opioid-induced hyperalgesia, and treatment-related adverse effects. Therapeutic cannabis has been proposed as an adjunct in multimodal pain management, with potential opioid-sparing properties. However, the clinical relevance of this effect remains uncertain.
Methods. Available evidence on therapeutic cannabis and opioid use for chronic pain was narratively reviewed, focusing on opioid use, analgesic efficacy, quality of life, and safety outcomes.
Results. Current evidence suggests a possible opioid-sparing effect of therapeutic cannabis in selected patients with chronic pain, but findings remain inconsistent. Observational studies frequently report reductions in opioid use after initiating cannabis-based treatment, sometimes accompanied by improvements in pain intensity, sleep quality, and patient-reported quality of life. In contrast, randomized controlled trials have not consistently demonstrated a clinically meaningful reduction in opioid consumption. Interpretation is limited by heterogeneity across patient populations, pain conditions, cannabinoid formulations, THC/CBD ratios, dosing regimens, follow-up duration, and outcome measures. Overall, systematic reviews and meta-analyses indicate low-certainty evidence regarding opioid reduction. Reported adverse events are usually mild to moderate and include dizziness, somnolence, dry mouth, nausea, and cognitive symptoms.
Conclusions. Therapeutic cannabis may serve as an adjunct within individualized multimodal strategies for chronic pain management. However, current evidence is insufficient to support its routine use as an opioid-sparing intervention. Further prospective studies are needed to identify patients most likely to benefit, define optimal formulations and dosing strategies, and clarify long-term efficacy and safety. Future research should focus on identifying clinical phenotypes and pain conditions in which cannabis-based medicines may provide the greatest benefit while minimizing opioid exposure. The opioid-sparing effect of therapeutic cannabis remains clinically plausible but not definitively established. At present, cannabis-based medicines should be considered a potential individualized adjunct rather than a validated strategy for reducing opioid use in chronic pain.