Bupropion HCL (Wellbutrin)

• Generic name: Bupropion hydrochloride
• Brand/Trade names: Wellbutrin, Zyban
• Dosages: 75 mg, 100 mg immediate release tablets; 100 mg, 150 mg, 200 mg sustained-release tablets; 150 mg, 300 mg extended-release tablets.
• Pharmacologic category: Aminoketone antidepressant, Norepinephrine and Dopamine Reuptake Inhibitor
• Habit forming? No
• Pregnancy risk factor: C

Bupropion (Wellbutrin) is in the class of the drugs called Norepinephrine and Dopamine Reuptake Inhibitors (NDRIs). This medication is indicated for the treatment of major depressive disorder. Bupropion is used to relieve symptoms of depression such as feelings of changes in appetite, tiredness, sleeping too much, insomnia, sadness, worthlessness, loss of interest in daily activities, and thoughts of death or suicide. This drug is typically prescribed for depression when selective serotonin reuptake inhibitors (SSRIs) or tricyclic antidepressants (TCAs) are not able to be used or are not effective.

Brand name medication Zyban is used for smoking cessation.

Although not an approved indication, the combination of bupropion and either an SSRI or an SNRI is generally well tolerated and can boost antidepressant response. Augmenting antidepressants with bupropion has become a common strategy in the treatment of resistant depression. The results of clinical study have shown that bupropion SR added to the SSRI or venlafaxine (Effexor) in patients failed to response to an SSRI or venlafaxine can increase the number of responders [5].

Bupropion appears to significantly affect dopaminergic neurotransmission and may help with fatigue and sexual dysfunction induced by SSRIs of SNRIs (Effexor). A study by Papakostas and associates examined the impact of bupropion vs SSRIs on sleepiness and fatigue in patients with deprssion. The investigators pooled data from 6 double-blind, randomized clinical trials and found greater improvements in fatigue scores among both bupropion-treated and SSRI-treated groups than placebo-treated patients, and greater improvements in fatigue scores among bupropion-treated than SSRI-treated patients [6].

Bupropion may reverse SSRI-induced sexual dysfunction due to its dopaminergic effect. Bupropuon in addition to the SSRI produces produces an increase in desire to engage in sexual activity and frequency of engaging in sexual activity [7].

• Elimination half-life: The half-life of bupropion is 21±9 hr. About 20 hr of hydroxybupropion, about 37 hr of threohydrobupropion, and about 33 hr of erythrohydrobupropion.
• Metabolism: bupropion is metabolised in the liver. It has at least three active metabolites: hydroxybupropion, threohydrobupropion and erythrohydrobupropion. These active metabolites are further metabolised to inactive metabolites and eliminated through excretion into the urine.
• Excretion: 87% excreted in urine, 10% in feces, and 0.5% as unchanged drug.

• seizure disorder
• anorexia/bulimia
• use of MAO inhibitors within 14 days
• abrupt discontinuation of ethanol or sedatives (including benzodiazepines)
• use of other forms of bupropion
• hypersensitivity to bupropion or any component of the formulation

• low risk of weight gain
• does not lower libido, produce impotence or impair orgasms
• decreased risk of switch into mania in bipolar affective disorder compared with other antidepressants

• neuropathic pain
• enhancement of weight loss
• attention deficit hyperactivity disorder (ADHD)
• depression associated with bipolar disorder
• augmenting a partial response to SSRIs

The neurochemical mechanism of the antidepressant effect of bupropion is not known. Bupropion is a relatively weak inhibitor of the neuronal uptake of norepinephrine, serotonin, and dopamine, and does not inhibit monoamine oxidase. Bupropion produces dose-related central nervous system (CNS) stimulant effects in animals.

• 1. U.S. Food and Drug Administration. Wellbutrin XL U.S. Prescribing Information. Available at (PDF format)
• 2. U.S. Food and Drug Administration. Wellbutrin SR U.S. Prescribing Information. Available at (PDF format)
• 4. Goren JL, Levin GM. Mania with bupropion: a dose-related phenomenon? Annals of Pharmacotherapy. 2000 May;34(5):619-21
• 5. DeBattista C, Solvason HB, Poirier J, Kendrick E, Schatzberg AF. A prospective trial of bupropion SR augmentation of partial and non-responders to serotonergic antidepressants. J Clin Psychopharmacol. 2003 Feb;23(1):27-30.
• 6. Papakostas GI, Nutt DJ, Hallett LA, Tucker VL, Krishen A, Fava M. Resolution of sleepiness and fatigue in major depressive disorder: a comparison of bupropion and the selective serotonin reuptake inhibitors. Biol Psychiatry. 2006;60:1350-1355
• 7. Clayton AH, Warnock JK, Kornstein SG, Pinkerton R, Sheldon-Keller A, McGarvey EL. A placebo-controlled trial of bupropion SR as an antidote for selective serotonin reuptake inhibitor-induced sexual dysfunction. J Clin Psychiatry. 2004 Jan;65(1):62-7. PubMed