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Merck Sued Again

Over the past week, more lawsuits against Merck & Co, makers of the recalled drug Vioxx, gained traction.

Plantiffs claim that bone medication Fosamax caused osteonecrosis of the jaw. Merck is going to argue there’s no proof, and that they met the requirements to warn patients.

Who’s right?

What’s Fosamax?

Fosamax is a treatment for osteoporosis that promotes stronger bones to reduce risk of fractures. It’s a serious problem – the economic cost annually from osteoporosis related fractures is more than $10 billion.

The older you get, the higher the risk gets. One third of women have hip fractures by age 90.

Bones are often broken when someone falls down or trips, something that also happens more often with aging due to weakened muscles and reduced coordination.

Fosamax and its relatives prevent osteoclasts from resorbing bone tissue, which can help prevent further degeneration of bones. They were initially hailed as “miracle drugs” because they reduced risk of certain types of fracture by up to 50%.

The Claims:

Fosamax may hurt the bone in the jaw. Osteonecrosis of the jaw (ONJ) is when bone gets exposed and doesn’t heal properly. As you can imagine, it is extremely unpleasant and difficult to treat.

Does Fosamax cause it?

Merck says no. But the science almost surely points to an increased risk of ONJ. It may not be large, but it’s there, and even moreso for certain uses of the medication. Intensive use for certain acute conditions, for instance, has a very high rate of ONJ.

Upper range of estimates of ONJ sufferers puts it at 5,000, and the lower ranges less than 1,000. The lowest put it at several hundred. More than 10 million prescriptions for Fosamax alone have been filled since 1995.

But despite the small numbers, the damage is there, and Merck did not warn patients as clearly as the FDA warned them to in 2005, when the data became compelling.

Development of ONJ is typically associated with comorbid cancer. One analysis claims 46.5% of sufferers had a history of multiple myeloma, 38.8% metastic cancer, and 6.2% prostate cancer.  If true, this is important, because it makes a big difference in deciding whether or not to prescribe it.

Conclusion

It looks bad for Merck.

But they will pull out no stops in their defense and point to the general safety of the product, and attack the validity of the plaintiff’s complaints.

One of their likely tactics is to argue that the cases of ONJ developed before they knew of the risks and had an obligation to inform patients.  Considering that they didn’t fully follow the FDA’s instructions for warning, it looks like an uphill battle.

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Sources:

Down to the bone
A Review of the Literature on Osteonecrosis of the Jaw in Patients with Osteoporosis Treated with Oral Bisphosphonates: Prevalence, Risk Factors, and Clinical Characteristics
Osteochemonecrosis of the Jaws due to Bisphosphonate Treatments. Update