IT is being hailed as the new wonder drug and has captured the imagination of nicotine addicts across Britain.
Zyban, we are told, can help us stop smoking without suffering the usual withdrawal symptoms of moodiness and intolerable cravings.
There is even some evidence that the tablets can help people lose weight - instead of piling it on - as they go cold turkey.
So it is little surprise that smokers are clamouring for their doctors to prescribe the new medication, which was only made available on the NHS in Britain two weeks ago.
After all, 70 per cent of Britain's 12 million smokers want to give up.
But when people try to obtain Zyban - which does not contain nicotine but instead works on two key chemicals in the brain to make quitting easier - many are frustrated to find their GP is loath to prescribe it at present.
Some health authorities are also telling their doctors not to prescribe it yet.
One British expert, who has seen the medication in action, however, is Manchester GP Dr Chris Steele. He runs the biggest smokers' clinic in Europe and is also the resident doctor on ITV's This Morning.
Steele believes the reluctance of GPs to prescribe the treatment for smokers is disgraceful and he is equally scathing about health authorities who want to evaluate a drug that has already been assessed by the Department of Health and the Medicines Control Agency.
He claims: "I have been helping smokers for 25 years. The situation is there's a lot of aggression out there amongst GPs about this drug and also towards smokers.
"Neither GPs or health authorities say you can't have drugs for raised cholesterol or high blood pressure. When drugs for these conditions come out, we prescribe them.
"But when it comes to smokers and their smoking treatments, there's something set in their minds to refuse them these medications and it really is very unfair."
But does Zyban work? Steele says he saw 76 people in one evening who wanted to start taking the drug and a handful of his patients, who began taking the drug as soon as it came on the market, are now at the quitting stage.
People take the medication, while continuing to smoke during the first week - before stopping completely in week two of the treatment.
And Steele is impressed by what he has seen so far. Those using Zyban report that they are lighting up out of habit, rather than necessity, at meal times and when they are on the telephone. They are actively looking forward to the quit date so they can kick the habit once and for all.
But he warns: "It's not easy. It is never easy. People are still getting the tendency to want a cigarette out of habit and they are getting some craving but it is not so troublesome."
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