The study involved 24 patients with multiple sclerosis and central pain attending a hospital clinic in Denmark.
Patients were given either dronabinol capsules or identical looking placebo capsules for three weeks. Pain intensity in the last week of treatment was assessed and patients completed a quality of life questionnaire.
Pain intensity was significantly lower and pain relief was higher during dronabinol treatment than during placebo treatment. Pressure evoked pain also tended to decrease, and patients reported better quality of life with dronabinol compared with placebo.
Adverse events, including dizziness, were more frequent with dronabinol than with placebo during the first week of treatment, but these decreased during treatment.
Dronabinol has a modest but clear and clinically relevant analgesic effect on central pain in patients with multiple sclerosis and should be available for patients whose central pain is not sufficiently treated with alternative drugs, conclude the authors.