There is no strong evidence to back the use of a cannabis-based medicine developed for the treatment of multiple sclerosis, according to new research.
Sativex, which is due to be legalised in the State next year, is also very expensive, according to the research published by the British Medical Journal today.
Independent TD Luke “Ming” Flanagan, who has championed the legalisation of cannabis, said it was a pity the study wasn’t more positive about Sativex “but even a minor benefit is better than no benefit at all”.
He said many people had told him anecdotally they were using the drug successfully, and not just for MS.
Last September, the Department of Health said its expert advice was that Sativex was a “valid treatment option” and announced its intention to change the Misuse of Drugs Act, which classes cannabis-based products as controlled substances.
It said the Irish Medicines Board had completed an assessment and “based on quality, safety and efficacy, has recommended the approval of the product for the Irish market”. The followed a market authorisation request from the manufacturers, GW Pharma.
The drug, which is used in the form of a mouth spray, contains dronabinol and cannabidiol, chemicals found in the leaf and flower of the cannabis plant. It is the first cannabinoid preparation to be licensed for use in the treatment of muscle spasms in MS.
Sativex is intended for use as a second line treatment in patients in whom other options have failed. But the review published in Drugs and Therapeutics Bulletin found that the claims made for Sativex are based on limited trial data.
Overall, the trials did show a small difference in the numbers of patients whose symptoms abated compared with those taking a dummy (placebo) preparation.
But in many of these studies, Sativex was used for relatively short periods—from six weeks to four months. And none included an active ingredient with which the effects of Sativex could be compared.
Two of the trials included doses that exceeded the 12 daily sprays for which the preparation is licensed. One trial did not have sufficient numbers of participants to validate the results.
A third trial, which was properly designed, and did have sufficient numbers of participants, did not find any significant difference in symptom relief between those who took Sativex and those who didn’t.
Sativex costs around 10 times as much as other drugs used for the secondary treatment of MS muscle spasms, the study notes. “We believe that such limitations make
