Up to 90 per cent of MS patients endure painful muscle stiffness at some point during the course of their disease, which reduces their mobility and interferes with daily routine activities and sleep quality. But current treatments often fail to resolve symptoms fully, and can be harmful, as a result of which many MS patients have experimented with alternative therapies, including cannabis.
Adult MS patients with stable disease, from 22 different specialist centres across the UK, were either randomly assigned to cannabis extract (tetrahydrocannabinol) daily (144) or a dummy pill (placebo) (135) for a period of 12 weeks.
The treatments were given in gradually increasing doses from 2.5 mg up to a maximum of 25 mg for two weeks, followed by maintenance doses for the remaining 10 weeks. The aim was to see if cannabis extract alleviated or improved muscle stiffness, associated pain, muscle spasms, and sleep quality, using a validated 11 point rating scale.
After the first two weeks of treatment, 87 per cent of those taking the placebo were on the maximum daily dose compared with just under half of those (47%) taking the cannabis extract.
After 12 weeks, one in four patients treated with cannabis extract was taking the maximum daily dose compared with over two thirds (69.4%) of those taking the placebo.
At the end of the study period, the rate of relief from muscle stiffness was twice as high among those given the cannabis extract as those given the placebo. Muscle stiffness was alleviated in just under 30 per cent of those given cannabis compared with just under 16 per cent of those treated with the placebo.
This difference was evident after 4 and 8 weeks, and also extended to pain, muscle spasms and sleep quality, at all time points, the results showed.
The differences were most noticeable among patients not already using antispasmodic treatment, among whom almost 40 per cent of those taking the cannabis extract gained relief compared with just over 16 per cent of those taking placebo.
The rate of side effects was higher among those taking the cannabis extract and highest during the first two weeks of treatment. Nervous system disorders and gut problems were the most commonly reported side effects, but none was severe.
The authors conclude that the results of their trial indicate that cannabis extract could be a useful treatment for the muscle problems typical of MS, and could provide effective pain relief, particularly for those in considerable pain.