protease inhibitor + ritonavir + 2 nucleoside reverse transcriptase inhibitors

This is a combination antiretroviral therapy regimen for HIV infection. It consists of a **protease inhibitor** (PI) boosted with **ritonavir** and two **nucleoside reverse transcriptase inhibitors** (NRTIs)[2][5]. - **Mechanism of action:** - **Protease inhibitor:** Inhibits HIV protease, preventing viral protein cleavage and maturation, leading to production of noninfectious viral particles[2][3]. - **Ritonavir:** Acts both as a PI (at high doses) and primarily as a pharmacokinetic enhancer; it inhibits cytochrome P450 3A4, boosting levels of coadministered PIs[3][4]. - **NRTIs:** Inhibit HIV reverse transcriptase, blocking viral RNA conversion to DNA, halting virus replication[5]. - **Primary indication:** Treatment of HIV-1 infection in adults and children[2][5]. - **Common clinical use:** First-line or salvage antiretroviral therapy. Individual drugs within each class are selected based on viral resistance, prior therapy, comorbidities, drug interactions, and guideline recommendations[5].