(The Associated Press)- The AIDS drug cocktails that have saved the lives of countless adults have proved powerfully effective in children, too.

A four-year study of 1,028 HIV-infected children and teen-agers found that combining protease inhibitors with standard AIDS drugs cut the risk of death by two-thirds, to less than 1 percent annually. Some children improved dramatically.

"The children are acting as if they didn't have AIDS," said study leader Dr. James M. Oleske, director of pediatric infectious diseases at University of Medicine and Dentistry of New Jersey in Newark. "They started growing, they started gaining weight, they started enjoying life. They didn't develop infections as much."

Since 1996, most adult AIDS patients have taken cocktails consisting of protease inhibitors along with older medicines. The combination has greatly suppressed the virus and cut deaths. For many patients, AIDS - once regarded as a death sentence - has been reduced to a chronic disease.

Because of protease inhibitors and other advances, some children infected with the AIDS virus around the time of birth are now in college; doctors once worried they would not live to finish grammar school.

Until recently, however, many doctors were not sure if children would get the same benefit from protease inhibitors as adults do. Some doctors hesitated to prescribe the drugs because of side effects such as bone loss.

The latest study looked at children treated for HIV at 40 pediatric AIDS clinics around the country. Their doctors and their parents decided on the course of treatment for each child.

The findings were reported in Thursday's New England Journal of Medicine.

In 1996, when doctors had to guess at children's doses of protease inhibitors and there were no liquid forms for the very young, only 7 percent in the study were taking them along with standard AIDS drugs. Those problems were soon solved, and by 1999, 73 percent of the children in the study were taking protease inhibitors.

Meanwhile, the annual death rate of study participants dropped from 5.3 percent to 0.7 percent.

"This is a great study," said Dr. Sharon Nachman, director of the Maternal Child HIV Center at the State University of New York at Stony Brook. "It shows we've moved from a fatal disease to a chronic illness that can be treated."

Copyright 2001 The Associated Press. All rights reserved.