A new tool in the fight against pain for cancer patients has emerged in the form of a cannabis mouth spray.
The cannabis-based spray was used on a total of 177 patients by researchers from Edinburgh University. The device, which is like a mouth freshener, was found to have reduced pain levels by 30%.
The patients' mental state was not affected in the way that using cannabis would, thanks to careful development.
Smoking cannabis was not justified by the researchers who warned it could increase the risk of cancer.
The findings, which were reported in the Journal of Pain and Symptom Management, said that the spray works by activating molecules in the body called cannabinoid receptors. The receptors can stop the nerve signals being sent to the brain from the site of the pain.
Edinburgh University's Professor Marie Fallon said that the early results are "very promising" and demonstrate that cannabis-based medicines may deliver effective treatment for people with severe pain.
She added that prescription of these drugs can be very useful in combating debilitating pain, but it is important to understand the difference between their medical and recreational use.