FDA continues its review of abacavir: Evidence does not suggest an increased risk of myocardial infarction

Key Points

Available evidence reviewed by FDA does not suggest abacavir is associated with an increased risk of myocardial infarction, according to an updated safety communication released March 2011.

Abacavir is a nucleoside analog reverse transcriptase inhibitor (or NRTI) used to treat human immunodeficiency virus (HIV-1) infection. Based upon the results of several observational studies including "The Data Collection on Adverse Events of Anti-HIV Drugs (D:A:D) Study" and a single randomized trial, FDA launched a cardiac safety evaluation of abacavir in July 2008.

This most recent safety announcement comes on the heels of a meta-analysis presented at the 18th Conference on Retroviruses and Opportunistic Infections recently held in Boston.

Twenty-six eligible trials conducted between 1996 and 2010 were identified. These trials evaluated 5,028 patients receiving and 4,804 not receiving abacavir (mean follow-up of approximately 1.4 to 1.5 person-years in each group), and recorded a combined total of 46 myocardial infarctions during all trials' follow-up. Upon meta-analysis, no significant effect of abacavir on myocardial infarction incidence was noted (OR=1.02; 95% CI, 0.56–1.84; risk difference, 0.03%; 95% CI, –0.24%–0.30%).

While FDA wants prescribers to be aware of the conflicting data regarding abacavir and its effect on myocardial infarction, they are still endorsing the drug's use when consistent with approved product labeling. As before, the agency is also recommending that prescribers and patients be diligent in reporting any adverse events associated with abacavir use through the MedWatch system, including myocardial infarctions.

FDA noted in its press release that they "will continue to communicate any new safety information to the public as it becomes available."

Abacavir is currently available as an active ingredient in Ziagen, Trizivir, and Epzicom.

SOURCES

FDA. FDA Drug Safety Communication: Safety review update of abacavir and possible increased risk of heart attack. March 1, 2011. Available at: http://www.fda.gov/Drugs/DrugSafety/ucm245164.htm. Accessed March 3, 2011.

FDA. Early communication about an ongoing safety review of Ziagen (abacavir) and Videx (didanosine). Available at: http://www.fda.gov/Drugs/DrugSafety/PostmarketDrugSafetyInformationforPatientsandProviders/DrugSafetyInformationforHeathcareProfessionals/ucm070263.htm. Accessed March 3, 2011.

Ding X, Andraca-Carrera E, Cooper C, et al. No association of myocardial infarction with ABC use: an FDA meta-analysis [abstract]. Presented at: the 18th Conference on Retroviruses and Opportunistic Infections; February 27–March 2, 2011; Boston. Abstract 808.