Table 1. Anti-obesity drugs approved, rejected, withdrawn or revised by the FDA.

Drug	Company	Mechanism of action	Comments
Anti-obesity drugs presently on the market
Orlistat	Roche, GSK	Pancreatic lipase inhibitor	Approved for long-term use in 1999
Phentermine	Not available	Adrenaline reuptake inhibitor	Schedule IV drug, approved for short-term use
Diethylpropion	Not available	Norepinephrine/dopamine releasing stimulator	Schedule IV drug, approved for short-term use
Benzphetamine	Pharmacia	Norepinephrine/dopamine releasing stimulator	Schedule III drug, approved for short-term use
Phendimetrazine	Not available	Norepinephrine/dopamine releasing stimulator	Schedule III drug, approved for short-term use
Anti-obesity drugs that await for decisions
Contrave	Orexigen	Bupropion+naltrexone	The FDA requested data on long-term cardiovascular risk assessment in 2011
Qnexa	Vivus	Phentermine+topiramate	The FDA requested data on teratogenic potential in 2010
Anti-obesity drugs rejected by the FDA
Rimonabant	Sanofi-Aventis	CB1R antagonist	Not approved in the USA due to its psychiatric sideeffects and withdrawn from the European market in 2009 for increased risk of serious psychiatric disorders
Lorcaserin	Arena Pharma	Selective 5-HT2C receptor agonist	Not approved due to concerns over carcinogenicity observed in rats in 2010
Anti-obesity drugs withdrawn from the market
Fenfluramine and dexfenfluramine	Wyeth-Ayerst	5-HT2B receptor agonist	Withdrawn after reports of valvular heart damage and primary pulmonary hypertension in 1997
Phenylpropanolamine	Not available	Norepinephrine/dopamine releasing stimulator	Withdrawn for increased risk of hemorrhagic stroke in 2000
Sibutramine	Abbott	NA/5-HT reuptake blocker	Withdrawn for increased risk of cardiovascular events in 2010

5-HT, 5-hydroxytryptamine; NA, noradrenaline; CB1R, cannabinoid 1 receptor; FDA, Food and Drug Administration; GSK, GlaxoSmithKline.