COX-2 inhibitor pulled off market.

The recall of rofecoxib (Vioxx) raises the question of whether the heart attack and stroke risks uncovered in recent research are unique to this drug or common to other COX-2 inhibitors, the Oct. 9 Lancet declares in an editorial. "The short history of COX-2 inhibitors has been plagued by safety concerns,' according to the journal.

Celecoxib (Celebrex) and valdecoxib (Bextra) are the other COX-2 inhibitors widely marketed for pain and other arthritis symptoms. Such drugs suppress the COX-2 (cyclo-oxygenase-2) enzyme, a known inflammatory agent. The drugs quell inflammation and pain as effectively as aspirin or ibuprofen do, but with less irritation to the stomach.

In light of a Food and Drug Administration health advisory issued on Sept. 30, Merck & Co. of Whitehouse Station, N.J., took rofecoxib off the market.

The FDA approved rofecoxib in 1999. Soon afterward, studies hinted at a heart attack risk linked to blood clotting. In response, the FDA implemented a labeling change for rofecoxib in 2002 that included a warning.

A more recent study cinched rofecoxib's recall. It included 2,600 people taking the drug or a placebo in a study of rofecoxib's effect on colon polyps. The trial was halted when the risk of heart attack or stroke among those getting the drug for 18 months was 15 per 1,000 people, compared with 8 per 1,000 people receiving the placebo.

Before the recall, nearly 2 million people had rofecoxib prescriptions worldwide, including about 1.3 million in the United States.--N.S.