Study Supports Popular HIV Drug Regimen

WEDNESDAY May 14, 2008 -- The largest study of its kind supports the use of a popular three-drug regimen for HIV patients and suggests a cocktail of two classes of drugs is a good alternative.

But an older regimen works almost as well, said study lead author Dr. Sharon Riddler, assistant professor of medicine at the University of Pittsburgh.

"It's not like 10 years ago, where there were huge differences between regimens," Riddler said. "We're looking at relatively small differences, trying to fine-tune what actually works pretty well."

The revolution in AIDS/HIV treatment came more than a decade ago, when combinations of drugs known as "cocktails" entered the market. Patients infected with HIV or who had progressed to AIDS typically had to take numerous pills each day.

Now, pharmaceutical companies have managed to combine multiple drugs into two-pill regimens or even a single pill.

In the new study, published in the May 15 issue of the New England Journal of Medicine, researchers examined the medical records of 753 HIV-positive patients at 55 treatment centers. The patients took one of three regimens, two of which included older drugs known as nucleoside reverse transcriptase inhibitors (NRTIs). Doctors consider them to be effective, but they can cause a variety of side effects.

The researchers found that the combination of a drug known as efavirenz (also known as Sustiva) plus two NRTI drugs did a better job of keeping a lid on levels of the virus in the body. Only 24 percent of those who took the regimen saw their viral load -- a reflection of the amount of HIV in their body -- return to detectable levels.

The virus gained a foothold in one-third of those who took lopinavir-ritonavir plus efavirenz -- two drugs instead of the usual three -- and in 27 percent of those who took lopinavir-ritonavir plus two NRTIs.

The researchers reported that all three regimens boosted the immune systems of the patients who took them.

The findings may bolster the use of efavirenz-based treatments in people whose immune systems are moderately to significantly suppressed, such as those who took part in the study, Riddler said. "For the most part, it's a simpler treatment for patients," she said.

Efavirenz isn't for everyone, Riddler cautioned. "A certain proportion of people won't tolerate efavirenz, and it can't be given to pregnant women," she said. For those patients, regimens that rely on so-called protease inhibitors -- like lopinavir-ritonavir -- may make sense, she said.

The study also suggests that it isn't necessary for all patients to be on NRTIs, Riddler said. "That gives us the opportunity to begin to look at other potential combinations now that we have availability of a couple of new classes of drugs."

And still another expert weighed in on the study.

Rowena Johnston, director of research at the Foundation for AIDS Research, said the study "could actually make a difference in patients' lives," because it gives them more information to help them choose among treatments.

Still, doctors and patients will continue to consider a constellation of factors when they decide which drugs are best, she said. Among other things, she said, they can look at different ways of gauging the effectiveness of the drugs plus side effects and the simplicity of regimens.

"If you put those pieces of information together, you have a better chance of finding the (best) combination for you," she said.

More information

Learn more about HIV treatments from avert.org.

Posted: May 2008


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