FDA Qnexa ruling a surprise for good reason

Kathleen Blanchard's picture
Qnexa approval contrary to advice from nutrition experts

An FDA panel has approved a new diet pill, Qnexa, which is making big headlines. The weight loss drug is the first to be approved in 13 years and the ruling to approve the combination anti-obesity drug that contains phentermine and topiramate might be raising some eyebrows from nutrition experts; for good reason. The message has been there's no quick fix for obesity.

Phentermine in combination with fenfluramine, or Fen-Phen, was pulled from the market because patients began to develop leaky heart valves and pulmonary hypertension. Qnexa is a combination of phentermine and topirimate.

According to PubMed, in 1996, there were over 18 million prescriptions written for Phen-Fen.

Phentermine is also sold under the name Adipex – a drug that is used as ‘speed’ because of its effect on the nervous system.

According to an EmaxHealth report from Denise Reynolds, RD, “The company (Vivus) will conduct a post-approval trial to assess the risk of major heart complications that would involve over 11,000 patients over the next four and a half years.”

If Qnexa is approved, it will likely be reserved for a select number of individuals whose risk of heart disease from obesity is already high.

Drug companies have been chomping at the bit to get weight loss drugs approved. The market is ‘huge’, given the prevalence of obesity (pun intended).

A commenter on Consumer Affairs wrote, “I started using Phentermine in 2009 to help me lose weight. I had heard about it. I went to my doctor and she prescribed it. She said it was safe and it would be good for me to use. I did a lot of research on it and never saw anything that would be a specific side effect. I took it for 7 weeks. The first 3 weeks, I dropped 20 pounds. I was eating a regular based 1400 cal. diet with fruits and vegetables. In week 4, I was losing my hair. In week 5, my heart began racing even if I climbed a flight of stairs to go to my apartment. In week 6, my face was extremely pale. Looking back at photos, I looked very pale and almost grey.”


There is no way to tell if the weight loss benefit of Qnexa, which contains phentermine, or any other diet pill outweighs the risks – at least not until long-term studies are performed.

We have the tools needed for weight loss, but it does take time and commitment. Moving more, whether it’s in a chair, in the pool, or just standing up and getting off the couch or from the computer to stroll around the house - combined with cutting back calories - can help you shed pounds.

Gerard E. Mullin MD is a board-certified internist, gastroenterologist and nutritionist, director of Integrative GI Nutrition Services at the Johns Hopkins Hospital summed it up in his Huffington Post article “New Year, New Diet Confusion”.

Mullin said, “Weight management is an everyday struggle for many Americans and there is an abundance of quick-fix gimmicky diets on the market. When in doubt, seek consultation with a certified nutritionist, and consider programs and weight management centers that offer a personalized approach to your weight control. Finally, in addition to dietary changes, I recommend seeking out alternative therapies that have demonstrated benefit for weight control, such as behavioral therapy, dietary supplements such as green tea, acupuncture and mindfulness.”

The drug was originally rejected by the FDA over concerns of birth defects if it’s taken by women who may not yet know they’re pregnant, in addition to heart complications.

Phentermine can lead to high blood pressure and rapid heart rate. The FDA will decide the fate of the diet pill April 17. If it’s approved, Vivus has agreed to keep studying the drug to see if there are major adverse events.

The FDA panel’s ruling to approve Qnexa is a surprise to some nutrition experts; for good reason. Sanjay Kaul, a cardiology professor at UCLA Cedar Sinai Medical Center and a member of the FDA’s Endocrinologic and Metabolic Drugs Advisory Committee said Qnexa is so effective it “shifts the balance in terms of requiring a post-approval study rather than a pre- approval study.” Some might disagree.

Valvular heart disease associated with fenfluramine-phentermine
Connolly HM
August, 1997

Huff Post Healthy Living
“New Year, New Diet Confusion”
Gerard Mullin, MD
January, 2012

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