A new study adds to the evidence that cardiac risk is increased in Vioxx (rofecoxib) users, even in those without a history of heart attack. The results also show that at lower doses of Vioxx, concurrent aspirin use can reduce the risk and the risk decreases to normal levels after Vioxx is discontinued.

There has been a slew of reports concerning the risk associated with COX-2 inhibitors since Merck withdrew Vioxx from the market last fall. However, some results suggest that the risk is not significantly increased by use of these drugs in some patient populations.

Dr. James M. Brophy and colleagues at McGill University Health Centre in Montreal analyzed data from Quebec’s administrative health databases to examine associations between various nonsteroidal antiinflammatory drugs (NSAIDs) and the risk of a first heart attack. They reported their findings in the online issue of the Annals of Internal Medicine.

Included were nearly 114,000 persons who received an NSAID between 1999 and 2002. The subjects had an average age of 75 years at study entry and were followed for an average of 2.4 years. During this time, 2,844 patients were hospitalized for a first heart attack.

The heart attack risk for patients taking Vioxx was 24 percent higher compared with the risk of those not using an NSAID in the previous year. Those prescribed a dosage of 25 milligrams per day or higher had an even greater increased risk, at 73 percent.

Aspirin eliminated the excess risk for heart attack among patients on low doses of Vioxx, but did not reduce the risk in those prescribed high doses.

Heart attack risk was not increased by current use of celecoxib (Celebrex), regardless of dose, or by traditional NSAIDs, they add.

Nevertheless, “new agents with COX-2 inhibitory potency similar to or greater than that of [Vioxx] should be used only with extreme caution, even in populations at relatively low risk for cardiovascular events,” the authors advise.

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SOURCE: Annals of Internal Medicine, February 1, 2005 online issue.