Qsymia‎ > ‎

Qnexa Dangers

Qnexa Contains a Powerful Mind-Altering Sedative Drug That Causes Birth Defects, Memory Loss, Severe Mental Impairment, Parasthesias and Possible Heart Damage

Editorial by Weight-Loss Doctor Mark John Holland MD

It is early March in 2012. Several weeks have passed since the advisory committee to the United States Food and Drug Administration overwhelmingly recommended for the approval of Qnexa by FDA. As the timeline stands now, this means that the agency will make a formal decision sometime in April, 2012. While there is always a chance that the Agency could deny approval, nobody really expects that to happen. It is a virtual certainty that Qnexa will become an FDA approved prescription weight weight loss drug very soon.

That's a good thing, right?

Well, I wish I could feel better about Qnexa, but I have serious doubts about its safety (and remember, I am a weight loss doctor. I SHOULD love this drug). These doubts are informed by several lines of evidence: 
  1. My own experience as a bariatric doctor who has prescribed limited amounts of topiramate (the 'scary' part of Qnexa) to patients
  2. The medical literature which shows a very real risk for cleft palate birth defect, depression1 and heart problems
  3. Common sense which suggests that at the very least a drug that causes as much sedation and memory loss and parasthesia as Qnexa will inevitably lead to impaired driving, motor vehicle accidents and a host of other problems associated with sedative drugs.
Let me share with you the words of a patient of mine who took topiramate for weight loss. And let me be clear too, she took it from her primary doctor before she became a patient of mine and she took only 50 mg per day (less than the 90mg strongest Qnexa dose). This patient told me: 

" I couldn't remember driving to work. There were entire work days that I could not recall. Maybe if my job was something mindless then I might have been able to cope, but it wasn't. There is no way I could function with that drug in my system. It was scary." She added that she also suffered constant numbness and tingling in her fingers (called parasthesia).

Here is some raw data from my clinic from the year 2011: (note this this is not controlled data)

  • Number of patients prescribed topiramate: 25mg per day as a starting dose: 61
  • Number of patients prescribed topiramate 25mg per day as a starting dose who discontinued the medication within the first 28 days due to intolerable* side effects: 36
  • Number of patients prescribed topiramate: 25mg per day as a starting dose who discontinued the medication within the first 56 days due to intolerable* side effects: 41 (36 + 5)
  • Number of patients prescribed topiramate: 25mg per day as a starting dose who discontinued the medication within the first 84 days due to intolerable* side effects: 55 (41 +14)

* Intolerable side effects are here defined as ANY side effects severe enough to cause the patient to stop taking to topiramate 

The most common intolerable side effects were: (in order from most to least common): parasthesias, drowsiness & foggy thinking, memory problems, depression, altered sense of taste, headache

Does this look like a miracle drug to you? No, it doesn't to me either and I really wanted to it to work. Lord knows we need a really good and safe new weight loss drug. 

Of course the data I just presented are crummy. I admit it. I never intended to perform any sort of clinical study with topiramate, but in light of the current rush-to-approve by the FDA advisory panel, I decided to mine the data that I have in my patient charts to see what the raw numbers showed and they show about what I expected.

Vivus (the Maker of Qnexa) is Using a Slow-Release Topiramate That They Claim Reduces Side Effects

The problem is that Topiramate has a long "half-life" (it persists in the blood stream a very long time) so it's not clear how slowing down its absorption should make any difference. I suspect the "slow-release" formulation is actually a tactic to protect Vivus' patent through claims of "proprietary formulation". In other words, it's bunk.

Would You Want Your Doctor Taking Qnexa? Your Airline Pilot? Your Kid's Teacher? Your Cab Driver? The Guy Next to You on The Freeway?

While I am among the first to agree that obesity is a terrible illness that deserves to be treated medically, and while I myself have devoted twenty years of my career to treating obesity with medication, I just can't get on-board for Qnexa. It isn't merely that Qnexa has side effects, it's that the topiramate in it truly impairs people. The simplest analogy is this: it makes people drunk. It places them in a chemical straight-jacket. Yes, it really does produce weight loss but so does smoking three packs of cigarettes per day and so does a bad case of tuberculosis or a tapeworm. Do we really want millions of Qnexa zombies injected into our midst? Are you willing to spend months or years living in a nether-world of drugged-stupor to lose weight--especially when older and proven drugs like phentermine alone work almost (or exactly) as well when they are prescribed at higher-than-Qnexa doses? The advisory committee to the FDA has made an error in recommending Qnexa for approval. The FDA will probably follow. I hope they don't but they probably will and in that case, hang on because things are going to get ugly.

What About the Phentermine In Qnexa?

Qnexa Contains Very Small Amounts of Phentermine. In fact, the lowest does of Qnexa only contains 3.75 milligrams of phentermine. That is exactly ten times less phentermine than the commonly-prescribed 37.5 milligram dose available today. So is this tiny does of phentermine actually helping very much or is the "heavy lifting" of weight loss being performed by the topiramate? The latter I suspect. Basically Qnexa is topiramate with a sprinkling of phentermine. I strongly suspect the phentermine is there for patent protection purposes rather than efficacy. Topiramate is a very old drug whose original patent expired long ago and Vivus had to combine it with something else to get a new patent. Now, in the case of the high-dose Qnexa which contains 92 mg of topiramate and 15mg of phentermine, in that particular case, there IS enough phentermine to help.

Let me be clear on this point: the concerns I have about Qnexa do NOT relate to its phentermine content but rather to its topiramate. Phentermine has been on the market in the US and around the world for over fifty years and has an extremely good safety record. Topiramate is another matter.

How Will Qnexa Play-Out?

Let me quote a letter I wrote recently: 

"Since my crystal-gazing was so good on Qnexa this far, here is my guess as to its future: it will hit the market this summer to great fanfare. We will see hundreds of news stories about how amazing it is, etc, etc. Then, by next spring, a year from now, we'll begin hearing "horror" stories about it's side effects and pretty soon the lawsuits will start. I lived (and practiced) through fen-phen and that's EXACTLY how it played-out."

Here is a quote from  Dr. Sidney Wolfe, director of Public Citizen's Health Research Group. Dr. Wolfe was a member of the first FDA advisory committee of two years ago that recommended AGAINST approving Qnexa. I think his should be the last word:

 “a large proportion of people who will use this drug will be women of child bearing age. Therefore, we strongly agree with FDA’s conclusion that there is a high likelihood of exposed pregnancies to this drug."

 “millions of people will be using this drug. They drive. They go to school. They work. The cognitive effects, although acceptable for people who have seizure disorders, are too powerful for mainstream use as a treatment for obesity.”

Mark Holland, MD
March 5, 2012