FDA updates safety information for antiviral drug abacavir
The FDA has updated the safety information for abacavir and its increased risk of heart attack. Abacavir is an antiviral drug used in combination with other antiretroviral drugs to treat HIV-1 infection.

According to FDA, the evidence surrounding the drug has been conflicting. For example, previous observational studies and a randomized controlled trial (RCT) showed that the drug increased patients’ risk of MI, however, a meta-analysis of 26 RCTs conducted by the FDA showed no such increased risk related to abacavir.

The FDA recommends that healthcare professionals continue to prescribe abacavir, which includes the drugs Ziagen, Trizivir and Epzicom (all ViiV Healthcare). In addition, the agency said that patients should not discontinue the drug's use without first speaking to their physician.

During the meta-analysis, FDA used four databases to search for clinical trials that included a randomized abacavir treatment arm. All trials included a sample size greater than 50 and all were conducted between 1996 and 2010. The researchers looked at risk differences as the primary analysis.

MI outcomes were reported for 9,969 patients who were randomized to receive either antiretroviral regimen that included abacavir or a non-abacavir-containing comparison drug. The FDA reported 46 MI events—24 MI events in 5,028 subjects randomized to a abacavir-containing regimen and 22 MI events in 4,840 patients randomized to receive non-abacavir drugs.

The FDA reported no statistically significant association between MI and abacavir-containing drugs.

The agency has asked patients and physicians to report any adverse effects that may be related to the drug to the FDA’s MedWatch Program.