Paritaprevir (ABT-450) dihydrate is a potent, orally active and antiviral non-structural protein 3/4A (NS3/4A) protease inhibitor with EC 50 s of 1 and 0.21 nM against HCV 1a and 1b, respectively. Paritaprevir dihydrate is also a SARS-CoV 3CL pro inhibitor with an IC 50 of 1.31 μM. Paritaprevir dihydrate is metabolized primarily by cytochrome P450 (CYP) 3A. The plasma concentration and half-life of Paritaprevir dihydrate can be enhanced by Ritonavir (a CYP450 inhibitor).