Dronabinol provides a safe and effective treatment option in patients with symptoms of neuropathic pain associated with multiple sclerosis, according to findings from a randomized double-blind placebo-controlled trial published in European Neurology.
Investigators randomly assigned patients to receive dronabinol (n=124) or placebo (n=116), and evaluated mean weekly pain intensity using the Numerical Rating Scale.
Pain intensity was not significantly reduced by dronabinol vs placebo after 16 weeks of treatment (point reduction from baseline levels: 1.92±2.01 [30%] vs 1.81±1.94 [27%]). However, pain relief was found to be clinically relevant in all patients. Also, both groups demonstrated similar improvements in quality of life (evaluated with the 36-Item Short-Form Survey SF-36) at the end of treatment.
Adverse events were reported by 92.9% of study participants, and greater adverse reactions were observed in patients taking dronabinol vs placebo (50.0% vs 25.9%); however, with long-term use, adverse events associated with dronabinol were reduced.
The “pronounced placebo analgesia” observed in this study represents 1 limitation of the findings. According to the authors, patient expectations, a close relationship between patient and physician, and behavioral conditioning may have contributed to the increased responses to placebo.
Compared with pregabalin and opioids, which tend to have a high abuse potential, the study investigators noted that “a relative stable dose of dronabinol over a long period suggests that there is no tolerance development” or severe level of dependency.
Schimrigk S, Marziniak M, Neubauer C, et al. Dronabinol is a safe long-term treatment option for neuropathic pain patients. Eur Neurol. 2017;78(5-6):320-329.