Bupropion sustained release. A therapeutic review of Zyban.

BACKGROUND

Originally developed as an antidepressant, bupropion hydrochloride is a selective re-uptake inhibitor of dopamine and noradrenalin which was found to reduce nicotine withdrawal symptoms and the urge to smoke. Bupropion came onto the Australian market in November 2000 as a 150 mg sustained release preparation to be used as an aid to smoking cessation in combination with counselling. Following the PBS listing in February 2001, there was a dramatic increase in prescribing, and considerable public and professional attention focused on this drug.

OBJECTIVE

This review summarises the evidence on how bupropion sustained release (SR) works, its contraindications and risks, adverse effects, studies on efficacy and place in smoking cessation pharmacotherapy.

DISCUSSION

Bupropion SR is a useful oral and non-nicotine form of pharmacotherapy for smoking cessation. Efficacy has been demonstrated in two key published trials. In one of these trials efficacy was superior to nicotine patch. There is also evidence of efficacy in patients with mild to moderate chronic obstructive pulmonary disease. Bupropion SR is contraindicated in a number of conditions where there is an increased risk of seizures. This includes patients with a current seizure disorder or any history of seizures. It must not be used concurrently with monoamine oxidase inhibitors and interacts with medications which can lower the seizure threshold. Minor adverse effects such as insomnia, headache, dry mouth and nausea are common. Serious adverse effects are rare but include seizures (risk of 1/1000) and hypersensitivity reactions. The latter can manifest as skin rash and a serum sickness-like reaction.