Ziagen Doubles Heart Attack, While Videx Up Heart Attack Threat by 50 PercentApr 2, 2008 | Parker Waichman LLP
A commonly used AIDS drug appears to nearly double the risk of a heart attack, according to researchers with the Food and Drug Administration (FDA) yesterday. In a study published online by the medical journal Lancet, researchers stated another less frequently used AIDS drug also increased the chances of a heart attack, but by 50 percent. Experts said doctors should be aware of the increased risks, but do not recommend patients abandon the drugs: GlaxoSmithKline, PLC’s Ziagen and Bristol-Myers' Videx. AIDS drugs “are wonderful and lifesaving, but they do have toxicity problems,” said Dr. Charlie Gilks, an AIDS treatment expert at the World Health Organization (WHO). “It may be that we can continue to use them, but we need to be aware of their long-term problems.”
US health officials are reviewing the safety of the AIDS drugs and the FDA said the review "may result in the need to revise labeling for the products; however, until evaluation is complete, healthcare providers should evaluate the potential risks and benefits" of each HIV drug their patients take. Researchers reviewed heart attack risk among patients taking certain medicines from the NRTI class—nucleoside reverse transcriptase inhibitor—of AIDS drugs.
Experts have long thought AIDS drugs could cause heart problems and it is known that the drugs come with many side effects, including liver and kidney failure, chronic fatigue syndrome, hepatitis, and jaundice. Jens D. Lundgren of the University of Copenhagen and colleagues analyzed data from over 33,000 AIDS-infected people in Europe, the United States, and Australia to study long-term effects of five AIDS drugs. Patients were followed for up to five years and of 754 patients who suffered heart attacks, 192 had recently taken Ziagen, also known as abacavir, and 124 had recently taken Videx, also known as didanosine. Those on Ziagen had twice the risk of heart attack compared to patients on other AIDS regimens; those on Videx had a 50 percent higher chance. Risks disappeared six months after patients stopped taking the drugs.
The risk in men over 40 who smoked and were overweight rose to 20 percent, increasing the risk with Ziagen to nearly 40 percent. For those without known heart risks, the chances of a heart attack were low, between one-to-five percent; however, once on the drug, the risk ranged from two to nearly seven percent. No increased heart attack risk was found for patients on the other drugs in the study, which included zidovudine (AZT), stavudine (Zerit) or lamivudine (Epivir). All of the drugs block an enzyme the AIDS virus requires to multiply.
AIDS drugs are used in combinations, or cocktails, so that one or more can be switched with others if needed. “In developed countries, doctors have 24 different anti-retrovirals to choose from if one isn’t appropriate. But if that happens in resource-poor countries, it is not so simple,” said Gilks. As AIDS patients continue to live longer, experts said they would probably see more unusual side effects. “No drug is risk-free,” Lundgren said. “For all patients, it’s a matter of finding the right balance.”