Bupropion is an antidepressant that inhibits neuronal reuptake of dopamine and noradrenaline, and is a noncompetitive nicotine antagonist at nicotinic cholinergic receptors. In randomised controlled trials, bupropion combined with behavioural therapy and regular follow-up has been shown to be at least as effective as nicotine replacement therapy (NRT) for smoking cessation—and it may reduce relapse rates. The effectiveness of bupropion for smoking cessation has not been studied in patients who have not received behavioural therapy.

The drug is commenced while the person is still smoking, and a quitting date should be set in the second week of therapy (eg day 8)—but many stop sooner. It takes about a week for plasma steady-state levels to be reached. Doses higher than 300 mg daily are not recommended because of the risk of dose-dependent seizures.

Adverse effects of bupropion include nausea, rashes, facial swelling, insomnia and dry mouth. Serum sickness–like reactions can occur, and bupropion can precipitate mania in patients with bipolar disorder. There is a lack of studies on the safety of bupropion used after an acute coronary event. The most serious adverse effect, which occurs in approximately 1 in 1000 patients taking bupropion, is seizure. The risk of seizure is increased in patients with known risk factors for seizures (such as head injury) and in patients taking other drugs known to reduce the seizure threshold (eg other antidepressants, including the selective serotonin reuptake inhibitors, and antipsychotics).

Bupropion is contraindicated in patients with a seizure disorder (currently or in the past), bulimia or anorexia nervosa (currently or in the past), monoamine oxidase inhibitor treatment in the previous 14 days, abrupt withdrawal from alcohol or benzodiazepines, or central nervous system tumour.

There are no data on the use of bupropion in pregnancy, and it should be avoided.