Celebrex is in the same class of medicines as Merck 's (nyse: MRK - news - people ) Vioxx, but had been thought not to pose a heart risk as that drug did.

FORBES: Pfizer's Celebrex Risk Gets Worse

Bextra is in the same class of medicines as Vioxx, the Merck (nyse: MRK - news - people ) pill that was pulled from the market because it doubled the risk of heart attack and stroke.

FORBES: Pfizer Says FDA Warning Likely For Bextra