Decreased metabolism rate by atovaquone. Reduced absorption by clarithromycin. Increased C
max w/ lamivudine. Lowered phenytoin blood levels. Increased mean t
½ & AUC by probenecid. Decreased AUC w/ rifampicin. Inhibited intracellular phosphorylation of stavudine. Altered metabolism by aspirin, codeine, morphine, methadone, indomethacin, ketoprofen, naproxen, oxazepam, lorazepam, cimetidine, clofibrate, dapsone & isoprinosine. Increased risk of ARs w/ potentially nephrotoxic or myelosuppressive drugs.