Friday, March 30, 2007

Implications of Zelnorm's Withdrawl

Zelnorm (tegaserod maleate), a serotonin 5-HT4 receptor partial agonist indicated for the short-term treatment of women with irritable bowel syndrome (IBS) whose primary bowel symptom is constipation, was pulled today from the market by Novartis on the recommendation of the FDA. It had previously been reported to have rare instances of ischemic bowel associated with the drug's use and now appears to have rare, but significant, problems with ischemic cardiovascular disease after a retrospective review of 29 studies of the drug.
(CBS News) Earlier this year, Novartis gave the FDA the results of 29 clinical studies of Zelnorm for treatment of a variety of gastrointestinal tract conditions. The analyses showed 13 of 11,614 patients given Zelnorm had serious and life-threatening cardiovascular side effects, while just one of the 7,031 patients given dummy pills did, the FDA and Novartis said in separate statements.
This drug follows closely the pulling of Pergolide yesterday two months after reports in the New England Journal of Medicine demonstrated the problems with this drug causing valvular regurgitation (leakage). It seems we'll be seeing more and more drugs pulled after the Vioxx fiasco and closer scruitiny by the media and Congress. But the incidence of problems (0.012%) vs (0.0014%) is mighty small, especially when one considers that acetominophen (Tylenol®) liver toxicity approaches a 4% incidence in emergency rooms in the US and England. Will Tylenol® be next?

These withdrawls suggest that even retrospective meta-analyses of outcomes that demonstrate almost no side effects will be the expected norm for drug safety in the post-market drug survellance era we have entered. Certainly, the potential for litigation is significant if side effects and potential complications are not disclosed. However, while patient safety is always paramount, the risk/benefit ratio of any drug should be considered when it is prescribed and there may be circumstances when certain drugs with higher side effects are in the patient's best interest.

So now I'm confused. How do we compare the incidence rate of side effects of drugs we prescribe? Are some drugs held to a double standard? What drug safety level should doctors tolerate?

-Wes

via KevinMD.

2 comments:

Dr. Deborah Serani said...

The mean error gap does seem to be lessening. I often feel that there should be litigation limits. My hubby, an attorney, agrees as well. So hard to be in a healing profession when nothing is ever absolute.

Cathy said...

I don't understand why patients aren't given the information and then allowed to decide for themselves if they want to continue treatment, rather than have someone else always making the decisions for us.

I have taken Zelnorm every day (twice a day, 6mg) for the last 3 years. I have not noticed any of these problems. I also don't really take it for the normal things it is prescribed for.

I take it in conmbination with Nexium and carafate for severe acid reflux with barrett's and dysplasia. My Doc's started me on it, to push things (food) through quickly, so they would not be hanging around causing reflux. I also had a surgery back about 12 years ago that caused a very weak colon so this also helps that issue.

but you know what. I'm a grown adult and Im capable of understanding risks, so this should have been my decision if I want to continue taking it or not.
I also have never sued anyone in my life, and can't comtemplate that I ever would.

If these outcomes are so very important, then why aren't these tests done PRIOR to drugs getting FDA approval and being on the market for years?

I guess you can tell I'm ticked about this one.