During the past two years researchers have presented conflicting findings about whether abacavir -- found in the medications Ziagen, Epzicom, and Trizivir -- boosts risks for cardiovascular disease. Some studies have suggested it raises, by as much as 90%, the risk of a myocardial infarction -- a heart attack. Now, researchers at abacavir manufacturer GlaxoSmithKline are reporting their analysis of more than 50 clinical trials of the medication has revealed no increased risk.
Reporting in the May 1 issue of the Journal of Acquired Immune Deficiency Syndromes, the Glaxo team reviewed data from more than 9,500 HIVers who took abacavir and nearly 4,700 who did not take the drug. They found that while there was a slightly higher rate of myocardial infarction among those taking the drug, the difference was not statistically significant. "In this pooled summary," the researchers conclude, "we observed few myocardial events overall and no excess risk of myocardial infarction with abacavir therapy."
Because their data conflict with other studies on the medication, Glaxo officials urge additional, long-term studies to determine if there is a link between abacavir and cardiac problems. They also note that data on known cardiovascular risk factors, like elevated cholesterol and triglycerides or the presence of the biomarker C-reactive protein, was not available for all of the patients in their analysis, which could have affected their findings.
