Risk of AIDS higher if therapy stops and starts

Last Updated: Thursday, November 30, 2006 | 11:22 AM ET

CBC News

People who take a break from HIV therapy to reduce the side-effects are more than twice as likely to die than those who take a steady course of the drugs, researchers have found.

Lifelong antiretroviral therapy has helped to turn HIV/AIDS into a chronic disease, but the treatment can be difficult to follow, is expensive and may cause incapacitating side-effects.

Smaller studies have suggested it might be safe for patients to temporarily stop taking the medication if they appear to be doing well.

But now one of the largest trials on the strategy has shown that interrupting antiretroviral therapy more than doubles the risk of AIDS or death from any cause. The study appears in this week's issue of the New England Journal of Medicine.

"Quite unexpectedly, our results show that interrupting therapy increases the risk of serious non-AIDS-related events," said Dr. Wafaa El-Sadr, one of the trial's co-chairs, in a statement. She is a researcher at the Harlem Hospital Center in New York City.

The trial on nearly 5,500 people infected with HIV in 33 countries was stopped early when the advantages of continuing therapy were clear from the preliminary data.

In the study, about half of the volunteers were assigned to take the drugs continuously, while the others stopped when key immune system cells in the blood called CD4 cells reached a certain level. They resumed therapy when CD4 counts dropped too low.

People who stopped treatment were 2.5 times more likely to die or be hit by an AIDS-related infection, the team reported. They were also 70 per cent more likely to develop heart, kidney or liver problems.

About three per cent of all study participants died or developed AIDS-related illness. Of those in the stop and start group, 55 died from various causes, compared with 30 in the continual therapy group.

Cancer, cardiovascular disease, substance abuse and opportunistic infections linked to AIDS were the leading causes of death for both groups.

Risks, benefits of both strategies revealed

El-Sadr called the results a "major lesson" for HIV/AIDS trials that shows the importance of evaluating all illnesses and causes of deaths, not only those linked directly to AIDS.

"The prospect of lifelong treatment is difficult for people with HIV," said David Cooper, an HIV expert at the University of New South Wales in Australia who also worked on the study.

"We are gratified that [this] study has so clearly delineated the risk and benefits of these two strategies," he said in a statement.

Given the findings, doctors should no longer offer treatment breaks without at least monitoring the amount of virus circulating in a patient's blood, said Dr. Anthony Fauci, head of the U.S. National Institute for Allergy and Infectious Diseases, which funded the study.

"I think for practical purposes, it is the end," Fauci told reporters at an AIDS conference.

Among the study's authors, 14 reported receiving consultancy fees, advisory fees and other payments from pharmaceutical companies that make HIV medications.