July 18, 2012

FDA Approval of Diet Drug Qnexa Is Reckless

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

Note: The U.S. Food and Drug Administration late Tuesday approved Qnexa, a diet pill made by Vivus and renamed Qsymia, despite evidence that it poses significant risks but has little evidence of long-lasting weight loss.


As was the case for the diet drug lorcaserin (Belviq), approved last month despite concerns about heart valve damage, it also was reckless of the Food and Drug Administration to approve Qnexa. Research shows the medication increases heart rate, and four patients on the diet pill had non-fatal heart attacks during the clinical trials, while none of those on the placebo had heart attacks.

It is magical and delusional thinking for anyone to believe that a drug will turn off hunger without hitting other targets where it will do harm, usually to the cardiovascular system.

Several previous diet drugs have been withdrawn from the market because they increased cardiovascular risk, including sibutramine (Meridia) because of evidence of an increased risk of heart attacks and strokes, fenfluramine and dexfenfluramine (Redux) because of heart-valve problems, and ephedra because of heart attacks and strokes.

Doctors and patients as well as the FDA are desperate for a quick fix for obesity– desperate to the point where they are willing to risk patients’ lives.

Other serious problems identified in clinical trials with Qnexa, in addition to increased heart rate, a risk factor for cardiovascular disease, include:

? Frequent metabolic acidosis — Although many people can compensate for this drug-induced adverse effect, in the clinical trials Qnexa caused increased nephrolithiasis (kidney stones; 22 cases in the Qnexa groups, five in placebo); uncompensated metabolic acidosis also is a risk factor for heart arrhythmias.

? Cognitive damage — Memory impairment, decreased concentration/attention. Overall, cognitive-related adverse events occurred in 1.7 percent of placebo patients and 5.6 percent of mid-dose Qnexa patients.

? Birth defects (cleft palate/lip) — well documented with human topiramate exposure.

Public health cannot tolerate yet another drug approval for a diet drug not accurately assessed for cardiovascular and other risks, especially in light of suggestive findings of such risks with Qnexa.
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