It is considered to be one of several antidepressants with greater risk of hepatotoxicity.The prescribing information warns about bupropion triggering an angle-closure glaucoma attack. On the other hand, bupropion may decrease the risk of development of open angle glaucoma.Bupropion use by mothers in the first trimester of pregnancy is associated with 23% increase of the odds in congenital heart defects in their children.Bupropion has rarely been associated with instances of Stevens–Johnson syndrome. Psychiatric
The FDA requires all antidepressants, including bupropion, to carry a boxed warning stating that antidepressants may increase the risk of suicide in people younger than 25. This warning is based on a statistical analysis conducted by the FDA which found a 2-fold increase in suicidal thought and behavior in children and adolescents, and 1.5-fold increase in the 18–24 age group. For this analysis the FDA combined the results of 295 trials of 11 antidepressants in order to obtain statistically significant results. Considered in isolation, bupropion was not statistically different from placebo.Bupropion prescribed for smoking cessation results in 25% increase of the risk of psychiatric side effects, in particular, anxiety (about 40% increase) and insomnia (about 80% increase). The evidence is insufficient to determine whether bupropion is associated with suicides or suicidal behavior.In rare cases, bupropion-induced psychosis may develop. It is associated with higher doses of bupropion; many cases described are at higher than recommended doses. Concurrent antipsychotic medication appears to be protective.
The reductive pathways are by 11β-hydroxysteroid dehydrogenase type 1 in the liver and AKR7A2/AKR7A3 in the intestine leading to threo-hydrobupropion and by yet unknown enzyme leading to erythro-hydrobupropion.The metabolism of bupropion is highly variable: the effective doses of bupropion received by persons who ingest the same amount of the drug may differ by as much as 5.5 times (with a half-life of 12–30 hours), while the effective doses of hydroxybupropion may differ by as much as 7.5 times (with a half-life of 15–25 hours). Based on this, some researchers have advocated monitoring of the blood level of bupropion and hydroxybupropion. Chemistry
Bupropion is an aminoketone that belongs to the class of substituted cathinones and the more general class of substituted phenethylamines. The clinically used bupropion is racemic, that is a mixture of two enantiomers: S-bupropion and R-bupropion. Although the optical isomers on bupropion can be separated, they rapidly racemize under physiological conditions.There have been reported cases of false-positive urine amphetamine tests in persons taking bupropion. Synthesis
It is synthesized in two chemical steps starting from 3-chloro-propiophenone. The alpha position adjacent to the ketone is first brominated followed by nucleophilic displacement of the resulting alpha-bromoketone with t-butylamine and treated with hydrochloric acid to give bupropion as the hydrochloride salt in 75–85% overall yield. History
Bupropion was invented by Nariman Mehta of Burroughs Wellcome (now GlaxoSmithKline) in 1969, and the US patent for it was granted in 1974.