FDA Studying Heart Attack Risk with Ziagen, Videx

FDA has informed the health care community about ongoing safety reviews of several drugs. FDA is doing this as part of its commitment to inform health care professionals and the public about its ongoing drug safety reviews. Because the information is preliminary and there is scientific uncertainty, FDA is not taking regulatory action at this point, and is not advising health care professionals to stop using the drugs. FDA is continuing to evaluate the safety of these products, and will provide updates as more information becomes available.

One communication concerns the possibility of an increased risk of heart attack among HIV patients taking the nucleoside reverse transcriptase inhibitors Ziagen (abacavir) and Videx (didanosine). This information comes from an ongoing international study of over 30,000 HIV patients. This study did not address the heart attack risk with tenofovir or emtricitabine, two other nucleoside reverse transcriptase inhibitors.

Results to date show that patients on Ziagen or Videx experience an increased risk of MI that ranges from roughly 50 to 90 percent. The excess risk appears to be greater among patients with other risk factors for heart disease, to remain stable over time, and to be reversible if the drugs are stopped. When the manufacturers of these two drugs, GlaxoSmithKline and Bristol Myers Squibb, searched their own databases, they did not find an increased risk of heart attack.

FDA is continuing to evaluate the risk of heart attack with Ziagen and Videx. This evaluation may result in the need to revise the labeling for these products. In the meantime, clinicians should consider the potential risks and benefits of each antiretroviral drug they prescribe.

Again, these communications are preliminary information, and they are in keeping with FDA's commitment to inform the public about its ongoing drug safety reviews. FDA urges healthcare professionals and patients to report drug adverse reactions through FDA's Medwatch program (see link below).

Additional Information:

FDA MedWatch Safety Alert. Ziagen (abacavir) and Videx (didanosine). March 27, 2008.
http://www.fda.gov/medwatch/safety/2008/safety08.htm#abacavir

FDA MedWatch - Reporting Adverse Experiences to FDA.
http://www.fda.gov/medwatch/how.htm