Sufferers of chronic pain and multiple sclerosis (MS) who currently use cannabis to relieve their symptoms do so illegally in the UK.
Trials of cannabis-based medicines are also underway in the US and Canada, but they are less well-advanced than those in the UK. In Europe, a softening of attitudes towards recreational use of the drug is also apparent: Switzerland is making moves to come into line with Holland, where use of cannabis in licensed cafes is legalised, and several other European countries turn a blind eye to possession of small amounts of the drug.
The recommendation that doctors be allowed to prescribe cannabis-based treatments was made by the House of Lords Select Committee on Science and Technology in November 1998
"They didn't want to know," says Lord Perry, chairman of the inquiry. "It was a drug of addiction -- the therapeutic aspect was not being looked at." The committee hoped that future scientific evidence on therapeutic cannabis use might force the government to change its tune. Today's report outlines the conclusions of an inquiry set up to establish the state of such research.
"The good news is that we are one of the only countries in the world doing large-scale trials. We could be the first to generate real medical data," says Leslie Iverson, professor of pharmacology at the University of Oxford and specialist adviser to the committee.
The Medical Research Council has put up £1.5 million to fund two new trials into the use of cannabis in treating MS and pain after surgery. But progress has been slow -- one trial is only just recruiting patients and the other hasn't even got that far. The report suggests that the stigma surrounding cannabis is inhibiting research.
"If the research does turn out to be positive, there will still be a long way to go before a cannabis-based medicine is available," says Iverson. For one thing, no one is volunteering to sell it. "Big pharmaceutical companies won't have anything to do with it."
In contrast, private company GW Pharmaceuticals is well advanced in developing cannabis-based treatments. The company has produced a spray that delivers the drug under the tongue. This improves on available delivery methods: capsules, in which drug dosage is difficult to control, and smoking, which is seen as medically unacceptable.
The committee's report also expresses concern about the attitude of the Medicines Control Agency (MCA), the body responsible for licensing cannabis-based drugs. The MCA insists that cannabis be treated as a new medicine. This means that toxicology data on chemicals in cannabis extract must be collected, a process that could delay trials by as much as two years. "I'm pleased at the progress but concerned at the heel-digging going on," Iverson concludes.
But overall, the report detects a softening in the government's official line towards genuine therapeutic use of cannabis. It suggests that, presented with sufficient scientific evidence, the government is now likely to recommend licensing of these medicines. "They've suddenly woken up the fact that we're not asking for recreational use -- just that doctors can prescribe clinical preparations of cannabis to MS sufferers," says Lord Perry.
David Harrison of the Multiple Sclerosis Society agrees that the government is starting to come round now trials are underway. "We've been pushing for proper research for a long time and we're very pleased they're underway," he says.