Lopinavir-d8 is intended for use as an internal standard for the quantification of lopinavir by GC- or LC-MS. Lopinavir is a potent HIV-1 protease inhibitor (Ki = 1.3 pM for wild-type enzyme). It inhibits the replication of clinical isolates of HIV-1 (EC50s = 5-52 nM). Lopinavir reduces the infectious virus yield and viral RNA copy numbers in the culture supernatant of Vero E6 cells infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2; EC50s = 26.63 and 26.10 μM, respectively). It reduces lung and kidney viral load, bronchointerstitial pneumonia, and pulmonary inflammatory cell infiltration in a marmoset model of Middle East respiratory syndrome coronavirus (MERS-CoV) infection when administered in combination with ritonavir .
