US FDA finds no increased risk of heart attack with ViiV's HIV drug abacavir

Following an ongoing safety review of abacavir and a possible increased risk of heart attack, the US Food and Drug Administration has concluded that there is none. Abacavir is an antiviral used in combination with other antiretroviral drugs for the treatment of HIV-1 infection. Available medications that contain abacavir include Ziagen, Trizivir and Epzicom, which are manufactured by GlaxoSmithKline (LSE: GSK) and Pfizer's (NYSE: PFE) joint venture ViiV Healthcare.

There has been conflicting information on the potential increased risk of heart attack with abacavir treatment. An increased risk of heart attack (myocardial infarction or MI) has been seen in several observational studies and one randomized controlled trial (RCT) with abacavir. However, an increased risk of heart attack has not been seen in other RCTs and the safety database maintained by the drug manufacturer, said the FDA.

The agency conducted a meta-analysis of 26 randomized clinical trials that evaluated abacavir, which did not show an increased risk of MI associated with the use of the ingredient. Healthcare professionals should continue to prescribe abacavir according to the professional label. Patients should not stop taking their abacavir without first talking to their health care professional, said the FDA, noting that it will continue to communicate any new safety information to the public as it becomes available.