Liverpool, United Kingdom: Long-term administration of Sativex, an oral spray consisting of natural cannabis extracts, reduces neuropathic pain without inducing tolerance in multiple sclerosis patients, according to clinical trial data published in the journal Clinical Therapeutics.
Twenty-eight patients completed the two-year, open-label extension trial. Investigators reported that patients required fewer daily doses of Sativex and reported lower median pain scores the longer they took the drug.
Authors also reported that drug’s administration was not associated with an increase in patients’ use of other analgesics – noting that several of the study’s participants reduced or ceased their use of pharmaceutical pain medications while taking Sativex. It has been estimated that more than one out of four MS patients suffer from neuropathic pain.
"[Sativex] was effective, with no evidence of tolerance, in … patients with central neuropathic pain and MS who completed two years of treatment," investigators concluded. "The use of [Sativex], per se, did not lead to a … major increase … in the use of new analgesics, which over at least two years is … a further indirect measure of sustained effectiveness in [this] population."
Previously reported data on the long-term efficacy of Sativex has shown the drug to decrease spasticity and bladder dysfunction in patients with MS.
NORML Senior Policy Analyst Paul Armentano called the extension trial results significant. "Multiple sclerosis is a chronic, degenerative disease; its symptoms become more severe over time," he said. "Therefore, one would assume that patients would be increasing their daily drug administration in order to maintain their initial levels of pain relief. That they are not doing so indicates that patients are not becoming tolerant to the drug’s therapeutic effects. More importantly, this result may also be evidence that cannabinoids are, in fact, moderating the progression of this debilitating disease. "
In August, Canadian health officials granted regulatory approval to Sativex as an adjunctive treatment in adult patients with cancer pain. Canadian officials had previously approved the drug’s prescription use to treat MS-associated neuropathy.
Makers of the drug are seeking regulatory approval for Sativex in the United Kingdom, the European Union, and in the United States.
For more information, please contact Paul Armentano, NORML Senior Policy Analyst, at: email@example.com. Full text of the study, "Oralmucosal delta-9-tetrahydrocannabinol/cannabidiol for neuropathic pain associated with multiple sclerosis: an uncontrolled, open-label, two-year extension trial," appears in the September issue of Clinical Therapeutics.