Benefit to risk decisions, consideration of Qnexa and involving your doctor

An expert panel of the FDA voted 20 to 2 yesterday for approval of a new weight loss called QNEXA. This does NOT mean that the medicine will become FDA approved, it simply means that of 22 people taking an expert and considered review of a weight loss drug, 20 voted that the benefits of the indeed outweigh the risks of the drug and that they thought the FDA should approve it. 

[woman with anchor]  Millions of Americans struggle with weight gain, being overweight and with obesity. There is clear scientific evidence that being overweight or obese, contributes to risk of diabetes, heart disease and multiple addtional problems. Diabetes itself is a serious risk multiplier (roughly 4 times increased risk) for heart disease. Still, an ABC News correspondant (Elizabeth Vargas) asked an important question on Twitter today. She listed some of the possible side efffects of QNEXA and tweeted in an important way about this issue and her thoughts on benefits and risks. It's definately worth a closer look!

For fair balance, the Essential Guide to Prescription Drugs has ALWAYS had a listing of known benefits and risks in an attempt to try to help encourage a smart discussion between any patient and their doctor when they are hopefully collaboratively thinking about starting and then continuing any new medicine.

The experts on the FDA Endocrinologic and Metabolic Drugs Advisory Committee looked at the benefits of QNEXA on weight gain and balanced their thinking against possible risks of the drug. The full consideration of what they thought about is part of the committee agenda and is available on the fda website at The 20 that voted in favor of FDA approval by the FDA came to the conclusion that the benefits indeed outweighed the risks. While I did attend the 2010 FDA committee meeting when Qnexa first was reviewed, unfortunately, I did not attend this hearing, hence will not weigh in on any discussion. 

Previously on this site, it was posted that:

"Beyond the recommendation for approval, the FDA expert panel also brought forth a strong recommendation that a large disease and death (morbidity and mortality) study should be started. Similar to other medicines where there are certain benefit to risk questions and potential heart and blood vessel risks (cadriovascular), a risk evaluation and mitigation strategy (REMS) was recommended."

This is EXACTLY at the heart of what the FDA now must consider AND certainly relates to what the ABC correspondant so intelligently brought up. QNEXA has potential side effects of increased heart rate, blood pressure, possible kidney stone formation, memory loss and possible birth defects, perhaps others. The details of what the FDA must consider involves how frequent the possible side effects happen, in which patients they are likely to happen and any possible defects in the study or confounding variables that may have led to an artificially increased rate of side effects. For example, in the people who were studied, where they somehow more likely than a usual population to get kidney stones?

Beyond the FDA approval issue, consideration of any treatment always involves a benefit to risk thought process AND a patient specific risk to benefit consideration. For example, if a medicine is known to lead to possible birth defects, it can be given a category X designation on the official FDA drug labeling (package insert). This would tell any possible prescriber that the drug should NEVER be used in pregnancy.

If any degree of blood pressure change is noted, the question again becomes what is the degree of increase, when and in who does it happen? If the increase is small (1 or 2 mm of mercury), many clinicians might opt to prescribe and follow such a medicine, thinking that the weight loss benefit will work to lower blood pressure more than any possible increase from the medicine itself. If the increase in blood pressure is larger, possible treatment of any blood pressure increase, home blood pressure testing or weekly testing of blood pressure might be appropriate.

The FDA now will review what the expert advisory committee recommended. They certainly could require ongoing (pharmacovigilance or phase 4 post-approval study) of QNEXA AND follow what the panel suggested and create a risk evaluation and mitigation strategy (REMS). This could take the form of a patient Med Guide coupled with some recommendations for more frequent blood pressure and heart rate follow up for some reasonable time, then periodically thereafter.

There was a picture of a cannon placed at the beginning of this article and it was meant to represent QNEXA as a potent potential new weapon against overweight and obesity, slow and silent multipliers of risk for diabetes, high blood pressure, heart disease, kidney disease and death. The complete and valid thinking (that the FDA must undertake and then clinicians who might prescribe the drug) have to consider is the weapon pointing at a dangerous condition, versus possible side effects pointing at the patient.

Unfortunately, there as yet is no perfect medicine, only better drugs than what exist today with more favorable benefit to risk considerations.

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