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Cannabis the wonder drug?

At a secret location in the home counties of England, 15 000 cannabis plants are being grown quite legally. They are being bred from strains whose namesHindu Kush, Skunk, Northern Lights, Gloriaare redolent of the Amsterdam coffee house scene. Their psychoactive seed heads, which stand over two metres high, are carefully studiedbut never smoked. For these plants are being cultivated as part of the world's first commercial trial of medicinal cannabis.

The company behind the trial, GW Pharmaceuticals, based at Porton Down Science Park in Wiltshire, has had a rather good fortnight. Firstly, the home secretary, David Blunkett, announced on 23 October that the government would liberalise the law concerning possession and use of cannabis. He also indicated that he would be ready to license cannabis for medicinal use to treat multiple sclerosis and other conditions as soon as research trials were completed. Most commentators (including, albeit grudgingly, the Daily Mail leader writers) seemed to approve. On 24 October shares in GW Pharmaceuticals jumped from 13p to 108p.

Secondly, the press this week hailed cannabis as a wonder drug and a miracle cure. Under the headline "Cannabis proves a medical miracle," the Observer, a newspaper not normally known for its hype, reported on 4 November that the first clinical trials of cannabis were showing that it was "capable of transforming the lives of very sick people."

After decades of cannabis being condemned as one of the scourges of Western society, this all seemed a bit too good to be true. Were these claims going too far? What sort of evidence was available?

The source of the Observer's story was the BBC 1 Panorama documentary "Cannabis from the chemist," broadcast on 4 November. The programme looked at two separate trialsa pilot study (n=23) in East Anglia of the effects of cannabis on the pain caused by nerve damage, and the early stages of a much larger trial in Oxford of the effects of cannabis on people with multiple sclerosis. The programme did not make clear the total number involved in the latter trialits medical director said in passing that he had initially seen 20 patientsand based its conclusions on the experiences of Sandra, Tyrone, and Jo (n=3).

GW Pharmaceuticals is the only company in the United Kingdom that has been given a licence to grow cannabis for medicinal use. Panorama's journalists were the only ones to have access to those taking part in the company's trials. Alex, who had a spinal injury, and Sandra, Tyrone, and Jo, who all had multiple sclerosis, received daily doses of cannabis sprayed under the tongue. They all showed remarkable progress. Although none of them had expected to be cured, they all experienced relief from pain. Jo, the 58 year old wife of a school chaplain, had struggled to lift her legs before the trial but afterwards was able to lift them 25 times. She hailed the drug's effects as "miraculous," and her husband said, "It's not a word that either of us would use lightly."

Dr Willy Notcutt of the East Anglian pilot study said, "The results so far have exceeded what I dared hope for . . . we are seeing 80% of our patients getting good quality benefit from the cannabis." Some were getting almost total pain relief, he said. "We have seen their pain scores go down to zero."

View larger version (126K): [in this window] [in a new window]   Panorama reporter Steve Bradshaw amid legally grown cannabis

More dramatic claims were made by Professor Lester Grinspoon of Harvard Medical School, one of the world's leading proponents of medicinal cannabis. Although not involved in the trials, Grinspoon claimed that cannabis would "eventually be used by millions of people around the planet." Just as penicillin "was considered the wonder drug of the 1940s," he said, cannabis "will eventually be seen as the wonder drug of the 21st century."

On Panorama's website (www.bbc.co.uk/panorama) the next day, Philip Robson, medical director of the Oxford trials, expressed concern about newspaper "wonder drug" headlines. He said: "We have to keep this in perspective. This seems to be a medicine which is incredibly useful for people who haven't had very much luck with the standard medicines, and that is really good, but I think to talk about wonder drugs and miracle cures is way over the top."

But newspaper headline writers can hardly be blamed for their "wonder drug" approach to the story. Panorama had given them plenty to go on, concluding: "We could see the drug in the chemist in just two years." Admittedly, Grinspoon's wild optimism was balanced with words of caution from, among others, Susan Greenfield, professor of pharmacology at Oxford University, who said: "The very term wonder drug is very frightening." And it would have been odd if Panorama had not embraced the opportunity to follow this historic experiment. But the result was rather like a commercial for GW Pharmaceuticals, even though the company's name was never mentioned.

Footnotes

tjackson{at}bmj.com

Trevor Jackson. 

BMJ