Merck says the U.S. Justice Department has opened a criminal investigation into the company's handling of Vioxx and the Securities and Exchange Commission has begun an informal inquiry. Pfizer, meanwhile, says it is likely to add a "black box" warning on its pain killer Bextra.
The company made the disclosure in a regulatory filing. It withdrew the popular pain killer from the market in September following studies which found the drug increased the risk of heart attack and stroke in patients who took it for more than 18 months.
Merck has been criticized for dragging its feet in withdrawing Vioxx, which brought in as much as $2.5 billion per year. Merck has insisted it acted promptly. In a statement yesterday, the company said it withdrew Vioxx just one week after learning the results of a company-sponsored clinical trial that demonstrated Vioxx's risks.
In its filing yesterday, Merck said that as of Oct. 31, it was a defendant in about 375 Vioxx personal-injury lawsuits, involving about 1,000 plaintiff groups. It said it expects more lawsuits to be filed.
The Food and Drug Administration (FDA) estimates that Vioxx may have contributed to 27,785 heart attacks and sudden cardiac deaths between 1999 and 2003. The estimate is based on the number of prescriptions issued for Vioxx between 1999 and 2003.
Bextra
In its quarterly report yesterday, Pfizer said Bextra, which is similar to Vioxx, can sometimes lead to a serious skin reaction.
It a few cases, the reaction leads to Stevens Johnson syndrome, in which the immune system attacks itself to rid itself of a drug, in effect burning the patient from the inside out.
The syndrome leads to severe, painful blistering of the mucous membranes and skin. Patients often end up in the burn unit. the mortality rate is about 30 percent.
A "black box" warning is the most serious warning available for prescription drugs.
