LONDON: Hospital patients scheduled to undergo surgery are being asked to take part in trials to find out if cannabis can provide pain relief after an operation, doctors carrying out a study for Britain’s Medical Research Council said on Wednesday.

Around 400 surgical patients were to be recruited to take part in the trials being carried out at National Health Service hospitals throughout the country on behalf of the state-funded body.

Each patient was being randomly assigned to one of four oral pain relieving treatments containing either standardized cannabis extract, tetrahydrocannabinol (an active ingredient in cannabis), a standard pain relieving drug, or a placebo.

The pain relief and side effects were then being assessed over a six-hour period with patients being asked to respond to questions about their pain and feelings.

Anita Holdcroft, an anaesthetist from Imperial College London, who is leading the 500,000 pound ($800,000) trial, said anecdotal evidence suggesting cannabis could provide effective pain relief for a variety of debilitating conditions needed to be assessed scientifically.

She denied the patients would get “high”, but acknowledged some might experience a “feeling of wellbeing”, pointing out that other drugs in medical use could have this effect.—dpa