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In Approving New Diet Drug, FDA Ignores Crucial Safety Data

Statement of Dr. Sidney Wolfe, Director, Public Citizen’s Health Research Group

The Food and Drug Administration (FDA) today recklessly approved another diet drug, lorcaserin, the latest in a series of obesity-related pharmaceuticals that pose serious health threats. We expect that as with many of the other drugs, this one will be withdrawn from the market after the agency is forced to confront the many serious adverse health effects, such as heart valve damage, that will be reported.

In a last-ditch effort to keep yet another of these dangerous drugs off the market, Public Citizen on Tuesday wrote to FDA Commissioner Margaret Hamburg, warning her of the very negative consequences associated with lorcaserin (Belviq, manufactured by Arena Pharmaceuticals), and urging her not to approve it. Marketing this drug to a population besieged by obesity and desperate for relief is irresponsible and a mistake that will benefit only the company that makes it.

Also Tuesday, a recommendation against using diet drugs was published online in the Annals of Internal Medicine.* Referring to currently marketed diet drugs, the U.S. Preventive Services Task Force concluded that because of safety problems and a lack of data showing that people can keep weight off after discontinuing diet medications , the task force could not recommend that anyone use diet drugs.

Although an FDA advisory committee that reviewed lorcaserin voted to approve it, it did so reluctantly, particularly because of widely shared concerns about evidence of heart valve damage in people using the drug in clinical trials, Public Citizen’s letter to Hamburg said. This same adverse effect led the FDA to ban fenfluramine and dexfenfluramine, the “fen” components of Fen-Phen, in 1997.

When these last heart valve-damaging diet drugs were banned in 1997, the knowledge of this life-threatening adverse effect was known only after approval. But in this case, the FDA has known before today’s approval of lorcaserin that it could damage heart valves. The agency’s own advisory committee concluded that “[t]here’s probably not sufficient data at this time to rule out a clinically meaningful increase in the risk for valvular heart disease.”

There is no dispute that obesity increases the risk of heart disease, but thus far, combinations of diet and exercise are the only proven safe ways of reducing such risk. The history of diet drugs is littered with drugs such as sibutramine (Meridia), ephedra, the above-mentioned fenfluramine and dexfenfluramine, which were banned after enough damage to the cardiovascular system was documented following approval. Increasing such risk in people already at risk by approving lorcaserin is a total refutation of the preventive principle that should underlie the FDA.

*Screening for and Management of Obesity in Adults: U.S. Preventive Services Task Force (USPSTF) RecommendationStatement


Public Citizen is a national, nonprofit consumer advocacy organization based in Washington, D.C. For more information, please visit www.citizen.org.