This study assesses the effects of voriconazole, 200 mg, administered twice daily (BID), on the steady-state pharmacokinetics of atazanavir administered as atazanavir/ritonavir, 300/100 mg once daily (QD), in healthy participants with functional CYP2C19 alleles. The study also reviews the effects of atazanavir/ritonavir, 300/100 mg QD, on the pharmacokinetics of voriconazole, 200 mg, BID in healthy participants with functional CYP2C19 alleles.