Bupropion selectively inhibits the neuronal reuptake of dopamine, norepinephrine, and serotonin; actions on dopaminergic systems are more significant than imipramine or amitriptyline whereas the blockade of norepinephrine and serotonin reuptake at the neuronal membrane is weaker for bupropion than for tricyclic antidepressants. The increase in norepinephrine may attenuate nicotine withdrawal symptoms and the increase in dopamine at neuronal sites may reduce nicotine cravings and the urge to smoke. Bupropion exhibits moderate anticholinergic effects.

Bupropion, an antidepressant of the aminoketone class and a non-nicotine aid to smoking cessation, is chemically unrelated to tricyclic, tetracyclic, selective serotonin re-uptake inhibitor, or other known antidepressant agents. Compared to classical tricyclic antidepressants, Bupropion is a relatively weak inhibitor of the neuronal uptake of norepinephrine, serotonin, and dopamine. In addition, Bupropion does not inhibit monoamine oxidase. Bupropion produces dose-related central nervous system (CNS) stimulant effects in animals, as evidenced by increased locomotor activity, increased rates of responding in various schedule-controlled operant behavior tasks, and, at high doses, induction of mild stereotyped behavior.

Reduction of the carbonyl groupand/or hydroxylation of the tert-butyl group of bupropion.

Symptoms of overdose include seizures, hallucinations, loss of consciousness, tachycardia, and cardiac arrest.

1. Fryer JD, Lukas RJ: Noncompetitive functional inhibition at diverse, human nicotinic acetylcholine receptor subtypes by bupropion, phencyclidine, and ibogaine. J Pharmacol Exp Ther. 1999 Jan;288(1):88-92. Pubmed
2. Fava M, Rush AJ, Thase ME, Clayton A, Stahl SM, Pradko JF, Johnston JA: 15 years of clinical experience with bupropion HCl: from bupropion to bupropion SR to bupropion XL. Prim Care Companion J Clin Psychiatry. 2005;7(3):106-13. Pubmed
3. Thase ME, Haight BR, Richard N, Rockett CB, Mitton M, Modell JG, VanMeter S, Harriett AE, Wang Y: Remission rates following antidepressant therapy with bupropion or selective serotonin reuptake inhibitors: a meta-analysis of original data from 7 randomized controlled trials. J Clin Psychiatry. 2005 Aug;66(8):974-81. Pubmed
4. : Annual report on the results of treatment in gynecological cancer. Twenty-first volume. Statements of results obtained in patients treated in 1982 to 1986, inclusive 3 and 5-year survival up to 1990. Int J Gynaecol Obstet. 1991 Sep;36 Suppl:1-315. Pubmed
5. Thase ME, Clayton AH, Haight BR, Thompson AH, Modell JG, Johnston JA: A double-blind comparison between bupropion XL and venlafaxine XR: sexual functioning, antidepressant efficacy, and tolerability. J Clin Psychopharmacol. 2006 Oct;26(5):482-8. Pubmed