Bupropion: pharmacology and interactions

Abstract

Bupropion is a monocyclic aminoketone introduced into Spain for the treatment of depression with the extended release (XL) formulation that makes it possible to administer it in a single daily dose. It is metabolized in its principal active metabolite, the hydroxybupropion (OH-BUP) by the cytochrome P450 2B6 (CYP2B6), with a mean elimination half life of about 20 h. It is a norepinephrine and dopamine reuptake inhibitor with an almost null effect on the serotonin transporter. It has low (12%-35%) but persistent occupancy of the striatal dopamine transporter. It has no clinically significant effects on the histaminergic, muscarinic, alpha-adrenergic or domaminergic receptors. Its principal interactions are related with inhibition or induction of CYP2B6, responsible for the bupropion metabolism, or inhibition of CYP2D6 by bupropion. It should be used carefully together with drugs that decrease the seizure threshold. This is contraindicated during sudden suppression of alcohol or sedatives and during treatment with monoaminooxidade inhibitors. The present paper answers frequent questions posed during the clinical use of bupropion, especially under special clinical situations or during treatment with other common drugs. These situations include, among others, combined use of anti-seizure drugs, antipsychotics in psychotic depression, corticosteroids, antidiabetics, other antidepressants such as venlafaxin, oral contraceptives, hormone replacement hormone therapy, disulfiram, alcohol or abuse drugs and varenicline.