The nation’s largest health management organization is considering changing how it prescribes Vioxx after a government study showed that high doses of the arthritis drug tripled patients’ risk of heart attacks and sudden cardiac death.
The study compared the outcomes of 40,405 Kaiser Permanente patients who took Pfizer’s Celebrex and 26,748 patients who were prescribed Merck & Co.’s Vioxx. The results of the Food and Drug Administration’s research were presented Wednesday at an epidemiology conference in France.
Heart attack rates tripled for patients taking Vioxx in doses higher than 25 milligrams per day, according to the study. Lower doses of the drug also increased the risk of a heart attack, “but not significantly so,” the study indicated.
Merck defended the safety of its $2.5-billion-a-year drug and questioned the study.
“Observational analyses do not have the rigor of randomized, controlled clinical trials,” Peter S. Kim of Merck Research Laboratories said in statement. “Based on all of the data that are available from our clinical trials, Merck stands behind the efficacy and safety, including cardiovascular safety, of Vioxx.”
But the study’s principals said “this and other studies cast serious doubt on the safety” of high doses of Vioxx. From the perspective of healthy hearts, Celebrex “may be safer” than Vioxx, they wrote.
Mirta Millares, Kaiser Permanente’s manager of drug information services and pharmacy outcomes research, could not say whether that also is the health maintenance organization’s conclusion.
Kaiser will review and discuss the study before acting. “We’ll also be looking to the FDA to see what their response is to the data.”
The most harm to patients’ hearts was associated with a dose that is twice the highest approved dose of Vioxx. Millares could not say why Kaiser doctors prescribed such high doses of the drug.