The U.S. government stopped a trial of AIDS drugs on Wednesday aimed at finding out whether patients could take breaks from treatment, saying people were much more likely to become ill or die if they took breaks.

The trial quickly showed that patients do better when they continuously take the drugs, said the National Institute of Allergy and Infectious Diseases (NIAID).

Some smaller studies had suggested that patients could safely take carefully monitored breaks from the strict regimens of drug cocktails that keep AIDS at bay.

But the larger, international trial showed that patients had twice the risk of dying or developing clinical AIDS if they took breaks from the drug cocktails, called highly active antiretroviral therapy, or HAART.

"Furthermore, there was an increase in major complications such as cardiovascular, kidney and liver diseases in the participants on the drug conservation arm," the NIAID said in a statement.

"These complications have been associated with (HAART), and it was hoped that they would be seen less frequently in those patients receiving less drug," it added.

The drug cocktails also cause nausea, diarrhea and other discomforts, and patients can build up resistance to the drugs, meaning the virus evolves and the drugs work less effectively over time.

The hope was the breaks would minimize these effects.

"We were surprised to learn that in the short term, episodic antiretroviral therapy carries such an increased risk without evidence of sparing patients the known side effects associated with ART (antiretroviral therapy)," said Dr. Wafaa El-Sadr of the Harlem Hospital Center and Columbia University in New York, who was working on the trial.

During the study, known as Strategies for Management of Anti-Retroviral Therapy, or SMART, patients either continuously took their drug treatments, or started only when numbers of key immune cells, called CD4 T-cells, dropped below a certain level.

When the trial was stopped, it was running in 33 countries with more than 5,000 patients taking part.

AIDS advocates welcomed the findings.

"It is important to emphasize that the cessation of SMART does not necessarily mean that all treatment strategies involving interruptions of antiretroviral therapy are dangerous, just that the specific approach employed by the SMART study design was less successful at preventing clinical events than continuous treatment," The Treatment Action Group said in a statement.

"There is a large body of data suggesting that individuals who initiate therapy with relatively high CD4 counts can safely interrupt therapy."

In a second study on HIV therapy published on Wednesday, researchers said they had shown one combination was clearly better than another for patients just starting out on HAART.

The report, published in the New England Journal of Medicine, showed that taking the three drugs Viread, known generically as tenofovir, Emtriva, known generically as emtricitabine, and Sustiva or efavirenz suppressed the virus better with fewer side effects, than the older combination of AZT and 3TC (sold as a one-pill combination called Combivir), plus Sustiva.

"The implications are quite clear for patients with HIV who are about to start therapy: The simple combination of tenofovir and emtricitabine, plus efavirenz, is likely to be highly potent with minimal side effects or long term toxicity," said Dr. Joel Gallant of Johns Hopkins University in Baltimore, who led the study.

http://news.yahoo.com/s/nm/20060119/sc_nm/aids_treatment_dc