bupropiona

Bupropiona, known in some countries as bupropión, is an antidepressant and smoking-cessation aid in the aminoketone class. It is used to treat major depressive disorder and seasonal affective disorder, and to help people quit smoking. It is available in several formulations, including immediate-release (IR), sustained-release (SR), and extended-release (XL), and is sold under various brand names such as Wellbutrin (depression) and Zyban (smoking cessation). Generics are widely available.

Mechanism of action is distinct from many antidepressants. Bupropiona inhibits the reuptake of dopamine and norepinephrine and also antagonizes central nicotinic acetylcholine receptors, contributing to its antidepressant and smoking-cessation effects. It usually does not cause sexual dysfunction and may be activating, which can help with fatigue or apathy in some patients.

Pharmacokinetics: Bupropiona is taken by mouth. Peak blood levels occur faster with IR and more slowly with SR/XL formulations. The apparent half-life is about 21 hours, with an active metabolite (hydroxybupropion) contributing to activity. It is extensively metabolized in the liver, primarily by CYP2B6, and is excreted in urine.

Dosing and administration: For major depressive disorder or seasonal affective disorder, typical regimens start at 150 mg/day and may be increased to 300 mg/day, given as divided doses (IR or SR) or as 300 mg once daily with XL. For smoking cessation, a common plan is 150 mg once daily for a few days, then 150 mg twice daily (total 300 mg/day) for 7–12 weeks.

Warnings and contraindications include a seizure disorder, a history of eating disorders, current or recent use of monoamine oxidase inhibitors, and abrupt withdrawal from alcohol or sedatives. Possible adverse effects include insomnia, dry mouth, headache, nausea, and, at high doses, an increased seizure risk. Pregnancy use varies by country; monitor closely.