ritonavir + cobicistat

Ritonavir + cobicistat is a combination of two pharmacokinetic enhancers used primarily in the management of HIV-1 infection as part of antiretroviral therapy. Both agents are potent inhibitors of cytochrome P450 3A (CYP3A) enzymes, which increases the plasma concentrations and effectiveness of coadministered antiretroviral drugs—especially protease inhibitors (PIs) and certain integrase inhibitors. Ritonavir was originally developed as an HIV protease inhibitor with antiviral activity but is now mainly used at low doses for its boosting effect. Cobicistat is a structural analogue of ritonavir that lacks antiviral activity but serves as a selective CYP3A inhibitor to enhance the pharmacokinetics of other antiretrovirals. The use of these boosters allows for lower dosing and improved efficacy or tolerability profiles for partner drugs[1][2][3][4][5][6].