The U.S. Food and Drug Administration has approved Viekira Pak (ombitasvir, paritaprevir and ritonavir tablets co-packaged with dasabuvir tablets) to treat patients with chronic hepatitis C virus (HCV) genotype 1 infection, including those with a type of advanced liver disease called cirrhosis. Viekira Pak contains three new drugs—ombitasvir, paritaprevir and dasabuvir—that work together to inhibit the growth of HCV. It also contains ritonavir, a previously approved drug, which is used to increase blood levels of paritaprevir. Viekira Pak can be used with or without ribavirin, but it is not recommended for patients whose liver is unable to function properly (decompensated cirrhosis). Viekira Pak is the fourth drug product approved by the FDA in the past year to treat chronic HCV infection.