More Evidence: Vioxx Increases Heart Risks
High Doses Linked With Heart Attacks, Sudden Cardiac Death

By Jeanie Lerche Davis, WebMD Medical News
Reviewed By Michael Smith, MD
August 26, 2004

The arthritis drug Vioxx may carry a higher risk of serious, even fatal heart problems than similar drugs such as Celebrex.

In a new study, patients taking higher doses of Vioxx (more than 25 mg daily) had triple the risk of heart problems, including heart attacks and sudden cardiac death.

There was a possible slight increase among those taking lower doses of Vioxx but not significantly so, reports lead researcher David J. Graham, MD, MPH, an epidemiologist with the FDA.

Graham presented his data this week at an international conference in Bordeaux, France. His study was based on medical records of patients treated at Kaiser Permanente, one of the largest health maintenance organizations in the U.S.

The new data are prompting Kaiser to take a closer look at Vioxx, says Mirta Millares, PharmD, director of Kaiser's pharmacy outcomes research program.

"We feel it is significant enough to take a closer look at the drug with rheumatologists and other experts in the field. We'll also be looking to the FDA for their analysis of this data," she tells WebMD. "It actually confirms the approach we've taken with Cox-2s all along. We reserve them for patients at highest risk for gastrointestinal toxicity."

Vioxx and Celebrex, along with the newer drug Bextra, are members of a class of anti-inflammatory drugs called Cox-2 inhibitors. They were developed to decrease side effects, such as stomach ulcer and bleeding, that are traditionally associated with older anti-inflammatory drugs such as aspirin, ibuprofen, and naproxen.

The Background

Earlier this year, a study suggested that taking both Vioxx and high blood pressure medications doubles the risk of a heart attack. Doctors should carefully consider using the drug in patients who are also being treated for high blood pressure, according those researchers.

Also this year, Canadian researchers showed an increase in heart failure among elderly people taking Vioxx. Compared with people taking Celebrex, Vioxx users were 80% more likely to be admitted to the hospital with heart failure.

Today's Study

The current study is a review of medical records for nearly 1.4 million patients with the health maintenance organization Kaiser-Permanente; more than 40,000 were taking Celebrex and nearly 27,000 were taking Vioxx; the others were taking traditional anti-inflammatory drugs like ibuprofen and naproxen.

Those taking more than 25 mg of Vioxx daily had a triple the risk of heart attack or sudden cardiac death.

Those taking lower doses of Vioxx were possibly more likely to suffer these serious heart problems, compared with all the other patients -- including those taking any dose of Celebrex. However, the risk didn't appear to be significant.

The painkiller naproxen increased risk by 18%.

Celebrex and ibuprofen did not affect the risk of severe heart problems.

From a heart-problem perspective, Celebrex "may be a little safer" than Vioxx, writes Graham. He admits that his study is limited by the low number of patients -- just 18 -- taking higher doses of Vioxx.

Although the FDA funded Graham's study, the findings do not reflect the agency's stand on the drug, according to the release.

SOURCES: FDA. Mirta Millares, PharmD, director, pharmacy outcomes research program, Kaiser Permanente. News release, Merck & Co. WebMD Medical News: "Vioxx, Blood Pressure Medications Don't Mix." WebMD Medical News: "Arthritis Drug Linked to Heart Failure."