Cox-2 inhibitors (Merck’s Vioxx and Pfizer’s Celebrex being the leading products) were introduced a few years back as being as effcective as older painkillers but without the stomach problems that affect about 30% of aspirin, ibuprofen or NSAID users. The most common ailment these drugs are targeted at is arthritis, but any long term low-grade pain is a candidate. Of course, they have been widely prescribed and used by people who either hadn’t been proved to have stomach problems on non-Cox-2 painkillers or are taking aspirin anyway. Additionally Celebrex has been alleged to actually not be as helpful for those with GI problems as it has been marketed to be. None of that news, almost all based on studies by PBM Express Scripts, seemed to affect the sales of Cox-2 inhibitors much, and it reamins a $6bn market.

But today a study from Kaiser Permante has a study out based on its own members data that suggests that Vioxx creates a three-fold risk of heart attacks compared to other NSAIDs and Celebrex. Merck’s stock price is down nearly 2% as a consequence, as presumably if this study gets come currency with physicians they might start switching patients to Celebrex or one of the newer Cox-2’s coming on the market later this year. If Merck is lucky those Cox-2s will include Arcoxia, Meck’s replacement for Vioxx which is undergoing FDA approval here, but is already on sale in Canada and Europe.