New findings may impact HIV drug use

HIV patients may have a greater chance of avoiding life-threatening diseases, after a breakthrough discovery by Sydney researchers. Britt Smith reports.

HIV patients may have a greater chance of avoiding life-threatening diseases thought to be associated with their treatment, after a breakthrough discovery by Sydney researchers.

The study looked at the impact of two leading anti-HIV drugs to determine if either were contributing to an increased prevalence of heart disease and heart attack among those taking certain medication.

The findings showed that Ritonavir, an older, commonly used drug, which was formerly linked to heart risk, had more adverse effects on people’s metabolisms than the newer drug, Raltegravir.

“Ritonavir looks like it’s increasing blood fat levels, not only when people are fasting but also after (eating) meals,” one of the researchers, Associate Professor Katherine Samaras, said.

It’s these “metabolic abnormalities” that set the stage for accelerated risk of heart disease, with the drugs causing weight gain around the abdomen, cholesterol increases and a resistance to insulin.

During the research, 20 volunteers without HIV infection were split into groups which took either Ritonavir or Raltegravir for one month.

Professor Samaras and co-researcher Professor Andrew Carr, both of the Garvan Institute of Medical Research and St Vincent’s Hospital, analysed blood fat levels, glucose sugar levels, insulin levels and the stiffness of arteries for six hours after the volunteers ate.

The post-meal surge in blood fat levels experienced by the Ritonavir group may be one of the factors explaining why people being treated with this type of drug are at a higher risk of getting heart disease, she said.

“There has been a lot of debate as to what drugs are doing it, and does the virus itself cause it,” Samaras said.

“We tend not to think the virus is causing these abnormalities.”

The discovery will have implications for clinicians in the west at least, but Samaras says people shouldn’t necessarily rush to stop taking the drug.

The key message, she says, is that each individual’s heart risk profile should be assessed before prescriptions are decided.

“When we weigh up the risks and the benefits of HIV treatment, we have to consider the best drug to stop the virus,” she said.

“If there are other drugs available that do the job equally well then it looks like (some) people should be considered for (a drug) that does not increase heart risk.”

About 17,500 people are living with the infection in Australia and 12,000 of those are younger than 50, according to the National Centre in HIV Epidemiology and Clinical Research.

“Twenty years ago we didn’t think people would survive 20 years with the infection,” Samaras said.

“And now they are surviving, they are doing quite well, and we are starting to see some of the diseases of old age much earlier than we would have expected to.

“But nevertheless we are trying to see how we can halt the progression to these diseases of ageing in people with HIV.”

The findings of the study are published in the journal AIDS, now online.

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