Bupropion

Bupropion (/bjuːˈproʊpi.ɒn/ bew-PROH-pee-on; marketed as Wellbutrin, Zyban, Voxra, Budeprion, Prexaton, Elontril or Aplenzin; and formerly known as amfebutamone) is an atypical antidepressant and smoking cessation aid. Its chemical name is β-keto-3-chloro-N-tert-butylamphetamine, a substituted cathinone (β-ketoamphetamine), as well as substituted amphetamine. The drug therefore is a mild psychostimulant. Its primary pharmacological action is thought to be norepinephrine-dopamine reuptake inhibition. It binds selectively to the dopamine transporter, but its behavioural effects have often been attributed to its inhibition of norepinephrine reuptake. It also acts as a nicotinic acetylcholine receptor antagonist. Bupropion belongs to the chemical class of aminoketones and is similar in structure to stimulants cathinone and diethylpropion, and to phenethylamines in general. Medically, bupropion serves as a non-tricyclic antidepressant fundamentally different to most commonly prescribed antidepressants such as SSRIs.

Initially researched and marketed as an antidepressant, bupropion was subsequently found to be effective as a smoking cessation aid. With over 20 million retail prescriptions in 2007, it was the fourth-most prescribed antidepressant in the United States retail market after sertraline, escitalopram, and fluoxetine.

Bupropion lowers seizure threshold, and its potential to cause seizures has been widely publicized. However, at the recommended dose the risk of seizures is comparable to that observed for other antidepressants. Bupropion is an effective antidepressant on its own but it is particularly popular as an add-on medication in the cases of incomplete response to the first-line selective serotonin reuptake inhibitor (SSRI) antidepressant. In contrast to many other antidepressants, bupropion does not cause weight gain or sexual dysfunction; in most studies, groups placed on bupropion showed statistically significant increases in sexual functioning (libido), and mild to moderate weight loss.