Description
Zyban (bupropion)
Zyban contains bupropion hydrochloride 150 mg in a sustained-release formulation and is used as a non-nicotine aid for smoking cessation. The same active ingredient at the same or higher doses is marketed as Wellbutrin for depression — the pharmacology is identical; only the indication differs. Bupropion inhibits dopamine and norepinephrine reuptake, and has antagonist activity at nicotinic acetylcholine receptors, which blunts some of the rewarding effects of smoking and reduces withdrawal symptoms.
Dosing
150 mg once daily for the first three days, then 150 mg twice daily for the remainder of the treatment course. The two daily doses should be taken at least 8 hours apart to maintain steady plasma levels and reduce seizure risk — do not double up on doses if one is missed. Treatment typically begins 1 to 2 weeks before the planned quit date. Maximum dose: 300 mg per day. Not for use before bedtime, as it causes insomnia in many patients.
Seizure risk
Bupropion lowers the seizure threshold in a dose-dependent manner. The risk is higher at doses above 300 mg/day and when combined with other drugs that lower the seizure threshold. Bupropion is contraindicated in patients with a current or prior seizure disorder, bulimia, or anorexia nervosa — these conditions independently elevate seizure risk. Abrupt alcohol withdrawal and use of benzodiazepine-lowering protocols also increase seizure risk in combination with bupropion.
Suicidality warning
Like all antidepressants, bupropion carries an FDA black box warning for increased suicidal thinking or behavior in children, adolescents, and young adults (up to age 24) during initial treatment. Monitoring for mood changes is required during the first weeks of use.
Contraindications
Seizure disorder or history of seizures. Bulimia or anorexia nervosa. Concurrent or recent use of MAO inhibitors (a 14-day washout is required before starting bupropion after stopping a MAOI). Abrupt alcohol or sedative discontinuation in high-dependence patients. Hypersensitivity to bupropion.
Drug interactions
Alcohol enhances side effects — avoid during treatment. Concurrent use of sedatives, antihistamines, and other CNS-active medications requires caution. Hepatic or renal insufficiency requires dose reduction. Bupropion inhibits CYP2D6, affecting metabolism of tricyclics, antipsychotics, and certain beta-blockers — inform prescribers of all current medications.
Side effects
Dizziness, nausea, diarrhea, headache, agitation, insomnia, and tingling sensations in the limbs are the most commonly reported. Dry mouth is common. Tachycardia and hypertension have been reported. Gradual dose reduction is recommended when stopping bupropion rather than abrupt discontinuation.