Health: When the drugs do work

Even over the telephone, you can tell that Walter Dale probably never smoked cannabis as a teenager. Not the type. Not the age-group. His teens were the early Fifties when cannabis simply wasn't around, unless you were a Jamaican saxophonist. By the time it appeared in the mid-Sixties, Walter was married, running a successful business and collecting old Jowett cars. If he wanted to adjust his brain, he used alcohol. Until his late- 50s, he was fit and healthy, but ageing humans, like ageing Jowetts, give trouble sooner or later. In 1995, he slipped a disc.

After an operation (courtesy of Bupa, so no delay), there was some residual pain. The surgeons said a little injection near the spine should do the trick. It probably does for 99 per cent of patients but Walter's legs were numb and paralysed the next day. Movement and feeling returned, but he was left with increasingly severe pain and weakness. Soon, he had to use two walking sticks and neither his GP nor the local pain specialists had an answer. Strong opiates didn't help and, in any case, he feared becoming addicted to them.

A few months ago, he read that cannabis sometimes relieved intractable pain. Overcoming his law-abiding habits, Walter obtained some. He wasn't very hopeful but five minutes after the first lungful, the pain was enormously better. Subsequent cannabis joints were equally effective. He told his GP who was, as always, sympathetic but couldn't legalise Water's successful self-medication with cannabis. Walter contacted Release, who normally advise youngsters arrested for possessing illicit drugs. Release referred him to me, though I specialise in addiction, not pain.

As I understood the legal situation, I could prescribe heroin for Walter but not cannabis, though it might become possible when planned clinical trials had been completed in a year or two. Of course, I'm all in favour of objective scientific trials, but I also believe that one of the primary duties of doctors is to relieve pain and that there's an important but unfashionable entity called "the art of medicine". In the absence of scientific evidence, I'm willing to use cautious empiricism to help my patients. Although I had never prescribed it, I knew of a synthetic cannabis preparation called Nabilone, used to control the severe nausea and vomiting which complicates some types of chemotherapy for cancer. I checked it out.

It wasn't even listed in the current MIMS (the pharmaceutical industry's monthly guide). The National Formulary mentioned it but warned that it was for hospital use only. The makers, Cambridge Laboratories (based, confusingly, in Tyneside), were very helpful and told me that in addition to its official, licensed use by hospital cancer specialists, any doctor could prescribe Nabilone for other purposes, provided the patient knows the drug is being used "off label", as the Americans say. This is not unique to Nabilone. Many drugs are prescribed "off label" because medical practice advances more quickly than medical bureaucracy. Prescribing "off label" exposes both patient and doctor to possible risks, and it must be done responsibly. But it is common in most areas of medicine. Nabilone isn't a "controlled drug" like morphine or dexamphetamine. It is actually in much the same legal category as many other drugs used to treat cancer.

I gave the good news to Walter's GP. He was afraid to prescribe it, so I referred Walter to an allegedly sympathetic pain specialist. He was sympathetic, but not enough to prescribe it. It seemed I would have to prescribe it myself. I took a history and examined him. He was clearly quite handicapped and there was obvious wasting of the leg muscles. After intoning the official "off label" warnings, I gave him a prescription. Two chemists then refused to dispense it, apparently on the grounds that anything involving cannabis was dodgy. After two weeks, one relented, though Nabilone cost Walter much more than his illicit cannabis. He had to pay pounds 117 for 20 capsules. They worked just as well, though the onset of relief was naturally slower than with smoking.

One capsule a day is usually sufficient. He still walks slowly, sometimes even without sticks or pain, and the only side-effect is slight nausea. Naturally, I have asked myself whether this is simply a placebo effect. It could be but the benefit has now lasted for over a month. We could easily give him some dummy capsules and see if he can tell the difference. The GP is impressed and accepts that he won't be dragged before the General Medical Council if he gives Walter an NHS prescription, but he still won't prescribe Nabilone because it costs so much and might be needed for several years.

Walter is 61 and married for a second time with three teenage children. He has had to retire from his business because of his disability, but at least he can live free of pain with Nabilone. What are we to make of this crazy situation? The official position (that we can't prescribe cannabis until trials have been done, and maybe not even then) is obviously incorrect. Nabilone is tetrahydrocannabinol (THC) - probably the main active constituent of cannabis. As with many new or under-researched treatments (especially drugs for Aids), clinical trials can be done in parallel with empirical use.

Cannabis isn't a new drug and clearly has relatively low toxicity. It shouldn't be dished out like Smarties (nor should Valium), but it shouldn't be denied to deserving cases like Walter just because of the USA's ineffective worldwide "war on drugs" during the last 80 years.

I don't easily believe in conspiracy theories but I do suspect that the government is terrified of offending the US and that there's at least a mini-conspiracy to pretend that Nabilone doesn't really exist. Or alternatively, to pretend that it can only be prescribed by cancer specialists for in- patients.

I don't say that it should be prescribed (especially on the NHS) to people who just want to get stoned, but it seems that most regular cannabis users prefer the real thing. I hope to get Walter enrolled in one of the trials expected to start soon, so that he won't have to pay about pounds 6 a day for a legal supply of a drug which, in a sensible world, he could grow at home for a few pennies.

Dr Colin Brewer is medical director of the Stapleford Centre in London, which specialises in addiction