March 1, 2011
From CROI, March 2011: An ongoing controversy in treating HIV disease is the possible role that the “accused” abacavir (Ziagen, Epzicom, Trizivir) has in causing an increased risk of heart attack. A few years ago, data from the D:A:D study suggested that abacavir increased this risk by 90%, and appeared to continue for 6 months after stopping the drug. That sent shockwaves through the research field, as the drug was listed a preferred choice in the US Guidelines at that time for people going on treatment for the first time.
Ever since, research teams have tried tackling the issue to confirm or negate the results. So far, it’s been a draw with about an equal number of studies supporting the D:A:D results while others do not. Scientists are still trying to find the bodily mechanism by which this may be happening, which in and of itself may mean something. But in the meantime, even with this FDA report, the right answer may still well be sitting on the fence.
By pooling data from similar research on abacavir, the FDA included 26 randomized abacavir studies from 1996 to 2010 that were completed in adults with more than 50 people each. Nearly 10,000 people were included in their analysis, separated into two groups: those on and those not on abacavir.
Two sets of analysis reported no connection between heart attacks and using abacavir. The first included all of the studies, whether or not they had reported heart attacks. The second analysis excluded 8 studies without reported heart attacks and showed 47 cases (25 on abacavir and 22 not). The FDA concluded that there wasn’t enough evidence to conclude that abacavir increases the risk of heart attack.
Although the FDA conducted a strict analysis of randomized studies, the only way to resolve this issue is to create a study that specifically addresses this issue, which may not happen anytime soon. Meanwhile, people who take abacavir or are considering it should talk to a knowledgeable provider about the pros and cons of this drug.
RESEARCH STUDY:
No association of myocardial infarction with ABC use: an FDA meta-analysis. Ding X, et al. 2011 CROI. Poster #808.