left<unk>  was originally developed as an inhibitor of HIV protease, one of a family of pseudo-C2-symmetric small molecule inhibitors.<unk>  is rarely used for its own antiviral activity but remains widely used as a booster of other protease inhibitors. More specifically,<unk>  is used to inhibit a particular enzyme, in intestines, liver, and elsewhere, that normally metabolizes protease inhibitors, cytochrome P450-3A4 (CYP3A4). The drug binds to and inhibits CYP3A4, so a low dose can be used to enhance other protease inhibitors. This discovery drastically reduced the adverse effects and improved the efficacy of protease inhibitors and HAART. However, because of the general role of CYP3A4 in xenobiotic metabolism, dosing with<unk>  also affects the efficacy of numerous other medications, adding to the challenge of prescribing drugs concurrently. Pharmacodynamics and pharmacokinetics The capsules of the medication do not have the same bioavailability as the tablets.<unk>  was demonstrated to have an in vitro potency of EC50=0.02µM and highly sustained concentration in plasma after oral administration in several species.
Ritonavir
Amprenavir
Saquinavir
Fosamprenavir
Indinavir
Nelfinavir
Atazanavir
Entecavir