One of the largest-ever studies of HIV treatment has found patients who temporarily stop taking their powerful medicines more than double their risk of dying.
Many HIV patients have sought doctors' permission to periodically take a break from the tiresome regimen of AIDS-fighting drugs, which can cause incapacitating side effects. Several small studies have suggested "holidays" from medication might be OK for patients who appear to be doing well.
But the new study of nearly 5,500 patients in 33 countries, published this week in the New England Journal of Medicine, suggests such a strategy can be dangerous: The rate of disease progression or death was more than twice as high in patients who took medications intermittently than in those who took them every day. However, many of the deaths were not related to AIDS, so it is not clear why the numbers varied, researchers said. About half of the study's patients were assigned to continuously receive AIDS drugs. The others stopped the therapy when key immune system blood cells reached certain levels and restarted when they fell below a threshold.
The second group's treatment breaks varied, but on average, patients were taking drugs 33 per cent of the time. Patients in the first group were on therapy about 94 per cent of the time. The study started in January 2002, but enrollment was stopped in January 2006, when it became clear that more people in the intermittent-treatment group were dying.
The numbers were small, however. Only 3 per cent of all participants died or developed AIDS-related illness. In the group that took drug holidays, 55 people died, compared to 30 in the group that stayed on their medication.
The leading causes of death in both groups included cancers, cardiovascular disease, substance abuse and opportunistic diseases associated with AIDS.
In the group that had interrupted drug therapy, another 65 people had nonfatal diseases like bacterial pneumonia, fungal infections and AIDS-related cancers. In the continuous group, 17 people had nonfatal infections.
"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 prepared statement. He is a researcher at the Harlem Hospital Center in New York City.
Fourteen researchers on the study have received consulting fees, advisory fees and other types of payments from pharmaceutical companies that make HIV medications, the journal reported.