Taking HIV drugs off and on is risky, report says

Taking HIV patients off medications during periods when the disease appears to be under control is a risky — and sometimes fatal — treatment strategy, according to a large international study published today.

Patients who cycled on and off drugs were 2.6 times more likely to die or develop symptoms associated with full-blown AIDS, compared with patients on continuous therapy, the study found. They were also 1.8 times more likely to develop serious heart, kidney or liver diseases.

Interrupted treatment once was seen as a promising way to reduce the toxic side effects of AIDS medications and to stretch the supply of drugs. But small studies over the past few years suggested it might do more harm than good.

The new report, published in the New England Journal of Medicine, appears to be the definitive word on this strategy.

"I think, for practical purposes, this is the end," said Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Disease, which funded the $73 million study.

HIV, or human immunodeficiency virus, attacks a class of immune cells called T-cells. Anti-retroviral drugs work by keeping the virus from replicating.

The rationale for interrupted treatment has been undermined in the past five years as AIDS treatments have become less toxic, said Dr. Eric Daar, chief of HIV medicine at Harbor/UCLA Medical Center in Torrance, Calif. Fears that patients would become resistant to AIDS antiviral drugs also have been alleviated by recent studies showing only a 5 percent rate of resistance, he said.

The study involved 5,472 patients in 33 countries.

Researchers stopped dispensing anti-retroviral medication to 2,720 of the patients beginning in 2002. The drugs were reinstated when the patients' T-cell counts dropped below 250 per cubic millimeter, or when there were other signs that their HIV was threatening to develop into AIDS.

In the group with interrupted treatment, 120 people, or 4.4 percent, died or developed AIDS-related diseases in a four-year period, according to the study. Of the 2,752 patients in the continuous treatment group, 47, or 1.7 percent, died.

Researchers expected rates of cardiovascular disease to be 15 percent lower in the drug interruption group because heart problems are a common side effect of the drugs. But 48 people in that group — compared to 31 on continuous treatment — developed cardiovascular problems, the study found.

A safety monitoring board halted the study in January and recommended that patients take medication full-time.