| Indication | For the treatment of depression and as aid to smoking cessation. |
| Pharmacodynamics | 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. |
| Mechanism of action | 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. |
| Absorption | For sustained release, peak plasma concentrations are achieved within 3 hours. |
| Volume of distribution | Not Available |
| Protein binding | 84 % |
| Metabolism | Reduction of the carbonyl groupand/or hydroxylation of the tert-butyl group of bupropion. |
| Route of elimination | Bupropion is extensively metabolized in humans. Oxidation of the bupropion side chain results in the formation of a glycine conjugate of metachlorobenzoic acid, which is then excreted as the major urinary metabolite. Following oral administration of 200 mg of 14C-bupropion in humans, 87% and 10% of the radioactive dose were recovered in the urine and feces, respectively. However, the fraction of the oral dose of bupropion excreted unchanged was only 0.5%, a finding consistent with the extensive metabolism of bupropion. |
| Half life | 24 hours |
| Clearance | Not Available |
| Toxicity | Symptoms of overdose include seizures, hallucinations, loss of consciousness, tachycardia, and cardiac arrest. |
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