Protease inhibitors are very effective in treating HIV-1 disease. However, patients who take these drugs often have problems, such as hyperlipidemia (an increased level of fat in the blood) and lipodystrophy (problems with the way fat is produced and distributed in the body). Doctors do not know exactly how PIs are related to these problems. APV has been shown to be safe and effective in lowering plasma viral loads (level of HIV in the blood). APV may be useful for patients who develop complications associated with other PIs.