AIDS Drugs Boost Risk of Heart Attacks

A widely used AIDS medication that was recently recommended as a preferred treatment may double a patient's risk of heart attacks in comparison to other AIDS drugs, according to a study conducted by researchers in Australia, Europe and the United States and led by researchers from the University of Copenhagen. The study was published by the journal Lancet.

Researchers reviewed data on more than 33,000 AIDS patients between 1999 and the present, and found that those taking the drug abacavir had a 90 percent higher heart attack risk than those taking other drugs.

In January, a federal panel officially recommended that a combination of abacavir and the antiviral drug 3TC (brand name Epzicom) be the "preferred choice" for AIDS patients receiving drugs for the first time.

"This [new study] is a head-scratcher, in the sense that we don't really understand the biology here," said Paul Dalton, director of Treatment and Advocacy for Project Inform in San Francisco, who served on the federal panel.

Since being approved by the FDA in 1998, abacavir has netted more than $1 billion in sales.

The new findings present a dilemma for doctors and patients, and not just because abacavir had become such a preferred treatment option. The very population that is most at risk from abacavir's heart effects, the researchers found, is people with underlying medical conditions that predispose them to heart disease, such as diabetes or high blood pressure. But the next most preferred AIDS drug, tenofovir, has a tendency to cause kidney damage, which that same population is also susceptible to.

The heart attack risk for patients taking most AIDS drugs is about three cases per 1,000, while the rate for those taking abacavir is closer to six.

Following the release of the new study, the FDA announced that it would conduct a review into whether regulatory action should be taken. But it emphasized that the study did not prove that abacavir is responsible for the elevated heart attack risk.