VIEKIRA PAK

Ombitasvir is an nonstructural protein 5A (NS5A) inhibitor that acts by inhibiting the HCV protein NS5A.

Ritonavir is an orally active peptidomimetic inhibitor of the HIV-1 and HIV-2 aspartyl proteases. Inhibition of HIV protease renders the enzyme incapable of processing the gag-pol polyprotein precursor which leads to the production of HIV particles with immature morphology that are unable to initiate new rounds of infection. Ritonavir has selective affinity for the HIV protease and has little inhibitory activity against human aspartyl proteases. Pharmacokinetic enhancement by ritonavir is based on ritonavir’s activity as a potent inhibitor of CYP3A-mediated metabolism.

Dasabuvir is a non-nucleoside inhibitor of the HCV RNA-dependent RNA polymerase encoded by the NS5B gene, which is essential for replication of the viral genome. Co-administration of dasabuvir with ombitasvir/paritaprevir/ritonavir combines three direct-acting antiviral medicinal products with distinct mechanisms of action and non-overlapping resistance profiles to target HCV at multiple steps in the viral lifecycle.