HIV-1 and HIV-2 protease inhibitor. Glucose transporter 1 (GLUT1) and 4 (GLUT4) inhibitor. Inhibits transport of glucose across the plasma membranes of mammalian cells and consequently decreases glycolysis. Useful agent for immunometabolism research. Antitumor agent. Apoptosis inducer and cell proliferation inhibitor in GLUT1/GLUT4 overexpressed cancer cell lines. Tumor cells rely on elevated glucose consumption and metabolism for survival and proliferation. Glucose transporters mediating glucose entry are key proximal rate-limiting checkpoints. Among the fourteen SLC2A family members, GLUTs 1 and 4 are high-affinity glucose transporters. The proteinase inhibitor Kaletra, which is a mixture of the HIV-1 proteinase inhibitors lopinavir and ritonavir has been shown to be effective against SARS-CoV and MERS-CoV. Shown in a SARS-CoV-2 protease structure model study to potentially bind and inhibit the coronavirus endopeptidase C30 (CEP_C30) of SARS-CoV-2. An initial randomized trial study was not successful.