Protease inhibitors are one of the most prescribed types of HIV drugs

GENEVA (CNN) -- The latest research presented at the International Conference on AIDS confirms that the promising new class of protease inhibitors is helping extend the lives of many patients, but with some potentially serious side-effects.

Don Mease says his doctors gave him the impression that there would be no problems with his protease regime. But that was not the case.

"...severe diarrhea problems, fatigue... I was having problems getting out of bed, I lost weight," says Mease.

He is not alone.

Doctors are discovering some otherwise thin patients are developing dangerous fat deposits, often at the waist line, and they are even more concerned about skyrocketing cholesterol levels in some protease patients.

"There have been tremendous lipid disturbances where their cholesterol and trigylcerides go through the roof, and as a result what we have seen has been several young people get coronary artery disease, " says Dr. Bruce Rashbaum.

So, doctors who once worried about their HIV patients dying of AIDS, are now worried about those patients suffering premature heart attacks.

But despite the problems, experts are not suggesting getting rid of one of the most-prescribed type of HIV drugs, and although few doctors ever thought they'd see long-term side effects in many of their HIV patients, they're not complaining about having drugs that help keep HIV from turning into AIDS.