IS THIS THE MIRACLE CURE FOR SMOKERS?

It's one of the most powerfully addictive drugs known to man ... and it may be about to meet it's match. Eddie Lennon reports on a new drug, currently being tested in Ireland, that could kill off our craving for cigarettes

A revolutionary new drug treatment for people who want to quit smoking will soon be available in Ireland. Zyban is now being marketed by pharmaceutical giant Glaxo Wellcome as a miracle cure for smoking, the first nicotine-free prescription treatment for kicking the habit.

Zyban started life as an anti-depressant drug and was used to help Vietnam veterans overcome the horrors of war. But in 1993, a Californian psychiatrist discovered that the Vietnam vets she was treating with the drug seemed strangely less inclined to smoke than before they started taking Zyban.

Subsequent investigations into Zyban's second dimension led researchers to discover that the drug staves off nicotine cravings. It's thought to lessen the bad moods, increased appetite and loss of concentration caused by giving up smoking, by correcting chemical imbalances in the brain caused by nicotine getting to the very root of the addiction itself.

Somehow the drug mimics the pleasurable "buzz" smokers get from cigarettes. Nobody really understands exactly how, but Glaxo Wellcome say it has nothing to do with Zyban's anti-depressant effect.

What is clear, though, is that Zyban is a powerful new ally in the battle against the killer cigarette. Smoking is an extremely dangerous habit. It's the single largest cause of preventable disease in the world, killing more people that Aids, alcohol abuse, road accidents, illegal drugs, fires, murder and suicide combined. It's also one of the most powerfully addictive drugs known to man.

Nicotine dependence is formally classified as a medical disease. It artificially stimulates the release of chemicals in the brain, creating a chemical imbalance, which the body has to adapt to. In fact, it's considered by the US Surgeon General more difficult to quit than heroin or cocaine. The World Health Organisation estimate that 30 million smokers in Europe tried to quit in 1998. More than 90% failed.

Nearly three million people have taken Zyban in the US since it went on sale as a stop-smoking drug two years ago. At least one million of them have quit. And in clinical trials, Zyban had almost double the success rate (people quitting for one year) of other therapies such as nicotine patches.

Zyban has since been approved for use in several other countries as a treatment for smoking addiction, including Canada and the Netherlands. It's also marketed in South America, Singapore and Switzerland. Worldwide, 4.2m people have successfully quit smoking by taking Zyban.

For the past few months, 30 Irish GP's have been testing Zyban on a total of 120 Irish people. The results of those trials are soon to be released, and offer real hope that Zyban could be the answer for Irish smokers who want to quit.

Dr Patrick Treacy of the Bray Family Practice is one of 30 GPs in Ireland who have been testing the effectiveness of Zyban. Four of his patients have been taking the drug twice a day for the recommended seven-week period. The treatment included three 'motivational sessions' with the individual doctors involved.

Dr Treacy said: "All my four patients who tried Zyban stopped smoking. One or two may have had one or two on the quiet, but Zyban helped them cut down from 20 to 40 cigarettes a day to two or none.

"All of them were over 40, and some had a fair bit of stress during the trials, but they were still fine. They said Zyban took away the craving. They could hold a cigarette in their hand without wanting to smoke it."

They gave regular samples of their saliva to measure the amount of nicotine in their bodies. Dr Treacy says Zyban helps people who are already motivated to quit. He feels two of his patients who took Zyban will stay off cigarettes, one will probably do so, and the fourth possibly.

But as with any drug that works by altering brain chemicals, Zyban does have some side effects. Most of these are similar to those you get when you quit smoking. Glaxo Wellcome say that most side effects are mild and temporary.

"The most common are dry mouth, insomnia, constipation, nausea and rash. In a small percentage of people, it can lower what's called the epileptic threshold. If somebody has the potential to have epilepsy, it may trigger it off. That happens in one in every thousand people who take Zyban."

People who may also be at risk when taking Zyban are those with a psychiatric history or those taking medication for psychiatric disorders.

Given the fact that an anti-depressant drug will soon be used to treat smoking addiction, the arrival of Zyban on the Irish market is bound to lead to some concerns being voiced about its safety.

Could treating smoking addiction with an anti-depressant not only be the biochemical equivalent of using a sledgehammer to break a nut, and perhaps a dangerous risk to take?

Dr Treacy feels that "if over four million people worldwide are on Zyban, that's a massive market already. There's no drug that's totally safe. Everything is a balance between what's good and bad for you. Considering that smoking is life threatening for half the people who smoke, any risks associated with Zyban are very small indeed."

Glaxo Wellcome have said that there is a one in 1,000 risk of getting a heart attack after taking Zyban.

With nicotine replacement therapy (NRT) in the form of chewing gum and nicotine patches, Dr Treacy says "you're effectively giving up smoking by taking a replacement for cigarettes nicotine into your body and desensitising yourself, whereas Zyban is more of a fresh start."

There have been two trials done to test how effective Zyban is compared to NRT. In one trial, smokers took Zyban, and later used nicotine patches. Zyban was twice to three times more effective than the patches. But Zyban was even more effective when people took the drug and used nicotine patches at the same time.

Dr Treacy is decidedly excited about the potential for Zyban. "If the Government puts Zyban on the medical card, it's possible that we will cut the number of smokers in Ireland dramatically overnight." Glaxo expect that Zyban will be on sale by prescription from early next month.