David Beresford's diary

This seems to be an age of particular uncertainty. It is an age when astronomers have realised that 90% of the universe is missing and particles have been found to be popping in and out of existence. At a more mundane level, the immediate certainties of medical science are collapsing by way of confusion over the benefits, if any, of routine procedures ranging from hormone replacement therapy to mammograms.

Journalism suffers something of a preoccupation with certainties in the form of "the truth". So, as a journalist trying to be more in tune with the times - and about to venture into a fresh arena of uncertainty by way of brain surgery next week - I am going to defy the professional pretension by writing an unfinished story, the significance of which I haven't the faintest clue. It is the curious story of a medicinal drug called apomorphine. The drug is, as the name suggests, an opiate developed more than a century ago in the same labs at Friedrich Bayer & Co that produced aspirin and heroin. Apomorphine was introduced to medicine as an emetic, to induce vomiting.

In the 30s a doctor specialising in addiction, John Yerbury Dent, discovered that a seemingly separate attribute of the drug from its emetic quality was its ability to ameliorate withdrawal symptoms. The drug seemed to remove the craving from addiction and took the fear out of going "cold turkey".

The American beat generation writer William S Burroughs was successfully treated for his drug addiction by Dent with the help of apomorphine, but the treatment never caught on. Confusion with its use in aversion therapy could have contributed to its lack of popularity. Burroughs himself (a man of considerable imagination) claimed the drug was the victim of a conspiracy among the US law enforcement agencies who nursed a prejudice against opiates in general and felt that addicts should suffer anyway.

Whatever the truth of it, apomorphine enjoyed yet another incarnation as an effective drug in the treatment of Parkinson's disease, but the nausea it induced meant it had to be administered by hourly injections, or an infusion pump implanted in the stomach. With the development of anti-nausea drugs and more efficient means of administration than injection - such as nasal sprays or patches - the drug still seemed full of potential where Parkinson's was concerned. Indeed, research published in 1999 found that apomorphine outperformed even L-dopa, the so-called "gold standard" drug in the treatment of Parkinson's. Unfortunately, funding for the research ran out before it was taken any further. Meanwhile, a fourth incarnation was awaiting apomorphine. One mysterious aspect of the pharmacological treatment of Parkinson's is the coincidence (based on anecdotal evidence) that most of the drugs used seem to have an impact on sexual activity.

When L-dopa, was developed in the mid-1960s the effect on erections was common gossip in the corridors of medicine. But it was not paraded in print. Similarly eldepryl, an adjunct to L-dopa in the treatment of Parkinson's, seems to help deal with impotence. Bromocriptine, another familiar drug to the Parkinson's patient, was the subject of a hefty out-of-court settlement of an £8.5m damages case last year in which a businessman complained that it had turned him into "a deranged sex maniac".

There are even recent research findings which suggest that the most famous of treatments for impotency, Viagra, can also help Parkinson's. So it came as no particular surprise to American researchers when they dosed 50 impotent volunteers with apomorphine in the mid 90s, to find them vomiting over their erections. A sub-lingual tablet (dissolving under the tongue) was quickly developed, which avoided the vomiting while maintaining the erection. The FDA has so far declined to licence it on safety grounds, complaining that, in addition to erections, it could cause dizziness and fainting, which it said was a potential hazard for motorists. In the EU, where there is presumably less of a demand on motorists to have erections while driving, apomorphine went on sale last year under the brand name Uprima, touted as Viagra's major rival to be the world's leading aphrodisiac.

Which is the end for now of a century-old, unfinished story, no doubt full of significance the nature of which I haven't the foggiest. Except to say I have not found a doctor who will administer it to me. Oh, for Parkinson's, of course.

Thanks to guardian.co.uk who have provided this article. View the original here.