Lopinavir is a dicarboxylic acid diamide with an amphetamine structure substituted on nitrogen by a (2,6-dimethylphenoxy)acetyl group and on the alpha-carbon to nitrogen by a (1S,3S)-1-hydroxy-3-{[(2S)-3-methyl-2-(2-oxotetrahydropyrimidin-1-yl)butanoyl]amino}-4-phenylbutyl group. It is an antiretroviral protease inhibitor used in HIV treatment as a fixed-dose combination with ritonavir. It functions as an antiviral drug, HIV protease inhibitor, and anticoronaviral agent. It belongs to the class of amphetamines and dicarboxylic acid diamides.
