Why the AIDS drug abacavir increases the risk of heart attack

Posted 11 August 2008

In spring 2008, a team of international researchers headed by the Copenhagen HIV Program from the University of Copenhagen, made the surprising discovery that the HIV drug abacavir almost doubles the risk of heart attack. At the time, the biological explanation remained unclear, and the producers of abacavir thus dismissed the findings. The Danish-led research team has now found a possible explanation and presented their new research findings at the world’s largest AIDS conference in Mexico. The researchers have discovered that abacavir makes arteriosclerotic coronary vessels unstable, which increases the risk of heart attack.

The researchers have analysed data from more than 4,000 HIV patients, and even though there was a clear correlation between the use of abacavir and the risk of different types of cardiovascular diseases, such as heart attack and stroke, there is no indication that abacavir in itself affects the arteriosclerotic process. Instead, it seems that a substance intended to fight HIV infections inconveniently also affects and increases inflammation in arteriosclerotic coronary arteries, thus making the sebaceous glands unstable. This is where abacavir doubles the risk of heart attack/myocardial infarction.

The research team also points out that the increased risk associated with abacavir is naturally most pronounced for HIV patients who already have a high underlying risk of heart attack, for example diabetics, smokers and people with, e.g., high cholesterol levels or a high BMI. As abacavir thus does not have any significant effect on people with a low risk of cardiovascular diseases, they can still use the drug. At the same time, the team concludes that HIV patients receiving abacavir should under no circumstances stop taking their medication, but should instead, if worried about the risk, contact their general practitioner.

The discovery will be published in the scientific journal AIDS on 2 September and has just been presented at the world’s largest international HIV/AIDS congress, the XVII International AIDS Conference, in Mexico by Professor Jens Lundgren from the University of Copenhagen.

Contact: Jens Lundgren, Professor of Viral Diseases Department of International Health, Immunology and Microbiology Tel.: +45 35 45 57 57 Email: jdl@cphiv.dk