Glaxo Wellcome hopes to market bupropion hydrochloride (Zyban) in the UK during the first half of 2000 as an aid to smoking cessation.
Bupropion, an aminoketone, has recently been approved for such use in the Netherlands. It is currently marketed in the US both as an aid to quitting smoking (Zyban) and as an antidepressant (Wellbutrin). According to Glaxo Wellcome, bupropion is believed to decrease craving and reduce the effects of withdrawal symptoms by acting on the addiction pathways of the central nervous system. Glaxo Wellcome says that a double-blind, placebo-controlled trial of 893 chronic smokers, who smoked 15 cigarettes a day, showed that bupropion sustained-release tablets were nearly twice as effective as a nicotine patch in helping smokers quit.
The study, carried out in the US, evaluated the efficacy of bupropion compared with a nicotine patch (Habitrol), a combination of bupropion and Habitrol and a placebo. Patients were randomised to one of the four treatments for nine weeks and followed up over a year. Throughout the study, bupropion combined with Habitrol was found to have higher success rates than the nicotine patch. However, this result was not significantly different from bupropion alone, says Glaxo Wellcome.
The company says that smokers should continue to smoke for up to two weeks after starting Zyban so that drug blood levels are maximised and smokers are eased into their "quit date", maximising their chances of quitting. The product is expected to be licensed as a POM.