Study: AIDS Drug Increases Heart Attack Risk

By Matthew Van Atta

Originally published on Advocate.com April 03 2008 12:00 AM ET

A commonly used
AIDS drug appears to nearly double the risk of a heart
attack, researchers said Tuesday. In a study published
online by the medical journal Lancet, the
researchers also said another less frequently used
AIDS drug increased the chances of a heart attack by 50%.
Experts said doctors should be aware of the increased risks,
but they did not recommend that patients abandon the
two drugs, Ziagen and Videx.

AIDS drugs ''are
wonderful and lifesaving, but they do have toxicity
problems,'' said Dr. Charlie Gilks, an AIDS treatment expert
at the World Health Organization. ''It may be that we
can continue to use them, but we need to be aware of
their long-term problems.''

AIDS drugs are
used in combinations, so they could be swapped with others
if necessary.

Experts have
suspected that AIDS drugs could cause heart problems, but no
definitive evidence has been available. The drugs come with
many side effects, including liver and kidney failure,
chronic fatigue syndrome, hepatitis, and jaundice.

Jens D. Lundgren
of the University of Copenhagen and colleagues analyzed
data from more than 33,000 people infected with the AIDS
virus in Europe, the United States, and Australia to
study the long-term effects of five AIDS drugs. The
patients were followed for up to five years to see who
had heart problems.

In the 754
patients who had heart attacks, 192 had recently taken
Ziagen, also known as abacavir, and 124 had recently
taken Videx, also known as didanosine.

Those who took
Ziagen, included in many AIDS regimens worldwide, had
twice the chances of a heart attack compared to patients on
other AIDS drugs, the researchers reported. Those on
Videx had a 50% higher chance. But the risk
disappeared six months after patients stopped taking the
drugs.

Lundgren said
patients already susceptible to heart problems were most at
risk.

For men over 40
who smoked and were overweight, the risk of a heart
attack were as high as 20%. Taking Ziagen increased that
risk to nearly 40%.

For those without
known heart risks, the chances of a heart attack were
low, between 1% to 5%. Once they were on the drug, their
risk ranged from 2% to nearly 7%.

No increased
heart attack risk was found for patients on the other drugs
in the study, zidovudine (AZT), stavudine (Zerit), or
lamivudine (Epivir). The medications all block an
enzyme that the AIDS virus needs to multiply.

GlaxoSmithKline
PLC, which makes Ziagen, said their own analysis of their
database of about 14,600 HIV patients, did not support the
Lancet study's conclusions.

''We were unable
to show any increased risk in heart attacks,'' said
Gwenan White, a company spokeswoman.

The findings
could influence how AIDS patients are treated globally, as
health authorities like WHO reconsider their treatment
guidelines. Ziagen and Videx are currently recommended
by WHO for people with HIV worldwide.

''In developed
countries, doctors have 24 different antiretrovirals to
choose from if one isn't appropriate. But if that happens in
resource-poor countries, it is not so simple,'' said Gilks,
who was not connected to the study.

As AIDS patients
continue to live longer, experts said they would
probably see more of the rarer side effects emerge.

''No drug is
risk-free,'' Lundgren said. ''For all patients, it's a
matter of finding the right balance.''

The research was
funded by the European Medicines Agency, a regulatory
group, which solicited contributions from makers of AIDS
drugs for studies on their long-term effects. (AP)