Newspaper reports cause concerns over the safety of Zyban (bupropion hydrochloride), the anti-smoking medication launched in the UK on 27th June 2000 -

18 deaths of patients taking Zyban have been reported. However, there is no evidence that these are related directly to Zyban.

Aetiology of 10 of these deaths have been identified:

• 4 Myocardial Infarctions
• 1 Acute Asthma
• 4 Brain Disorders
• 2 Suicides

The Context

At least 270 000 patients in Britain have commenced Zyban for smoking cessation. Worldwide, Zyban has been used by 5 million for smoking cessation, and another 10 million as an anti-depressant.

3457 possible adverse reactions have been reported so far. These consist mainly of:

• Insomnia
• Chest pains
• Dry mouth
• Rashes
• Nausea
• Depression

The other adverse reaction causing most concern is seizure:

• Expected rate is 1 in 1000 patients treated with Zyban
• Current British reported seizures total 73, a rate approximately equivalent to 1 in 4000

However, 3 cases of seizure have been treated at one UK hospital, so there may be an under-reporting of cases.

Past history or current seizure disorders are a contra-indication to Zyban. Caution is required where there are other risk factors for seizure:

Lowered seizure threshold - head trauma, CNS tumour, hepatic dysfunction, excess alcohol intake.

Medications lowering seizure threshold - antipsychotics, antidepressants, theophylline, systemic steroids, withdrawal of benzodiazepines.

Smoking-related conditions for which Zyban was prescribed may exist concomitantly. This obviously confounds the association of Zyban with fatal outcomes. There is no evidence that Zyban contributed to the reported deaths.