Blood Levels of Abacavir After One Dose in HIV-Infected Children and Adolescents

Inclusion Criteria Patients may be eligible for this study if they: Are 9 to 18 years of age. Are HIV-positive. Have a CD4 cell count above 200 cells/microL. Have a viral load (level of HIV in the blood) under 100,000 copies/ml. Have not changed their anti-HIV drugs for the 4 weeks before study entry. Are able to swallow study medications. Both males and females, agree to use a barrier method of birth control for 3 days after taking the abacavir dose for this study. (This study has been changed. In the earlier version, no birth control was needed.) Can be followed at a participating Pediatric AIDS Clinical Trials Unit (PACTU) for the entire study. Provide written consent of a parent or guardian, if under 18 years of age. Exclusion Criteria Patients will not be eligible for this study if they: Have liver or kidney problems, as shown by screening tests. Have medical or surgical problems that affect movement or absorption in the stomach or gut. Have an opportunistic (AIDS-related) or serious bacterial infection requiring medicine at the time of enrollment. Have any diseases (other than HIV infection) or other findings that, in the investigator's opinion, might make it harmful for the patient to be on the study. Have a history of chronic alcohol use. Fall outside of a certain weight range for their age. Are pregnant or breast-feeding. Are receiving or have received abacavir. Are receiving nonnucleoside reverse transcriptase inhibitors, including efavirenz, delavirdine, or nevirapine; hydroxyurea; mycophenylate; rifampin, rifabutin, anticonvulsants, or other drugs that affect the liver; or chemotherapy for active cancer. Have received interferons, interleukins, HIV or other vaccines, or experimental therapy within 30 days before entering the study.