A large trial of cannabis-based medicines has produced compelling evidence that they can help to reduce pain, say scientists. GW Pharmaceuticals has been given a licence by the UK government to test a range of cannabis-based prescription medicines. Its latest work focused on 34 patients with multiple sclerosis, spinal cord injury and other conditions causing severe pain. None of the patients had responded well to current medications, but 28 said that using cannabis-based treatments reduced their pain and helped them to sleep more soundly. Each patient was given three different types of medication which contained different levels of the active ingredients of cannabis. All out-performed a dummy medication. Remarkable findings The research was conducted by Dr Willy Notcutt, at his pain clinic at the James Paget Hospital, Great Yarmouth. He said: "Patients in this trial are suffering from severe pain - it dominates their lives. "Given the previously intractable nature of their pain symptoms, the improvements provided by cannabis-based medicines are all the more remarkable. "Many of those with chronic pain also suffer from a poor quality of sleep, which - over time - can have profoundly negative effects on them and their families. "By bringing about improvements in their sleep regime, as well their pain, we can have a major positive impact on their quality of life." The number of patients who took part in the trial is still relatively small, and further research is required before cannabis-based medicines are made widely available. However, Dr Geoffrey Guy, GW executive chairman, said: "We are delighted with the results of this study in patients with severe pain. "The data shows improvements with all three of our cannabis-based medicines and we therefore believe that there will be a market for all three medicines in pain treatment in due course." GW plans to release data about more advanced clinical trials later this year. copyright www.bbc.co.uk