Ombitasvir + paritaprevir + ritonavir (Viekirax). Hepatitis C: high risk of interactions and serious liver injury.

In patients with HCV genotype 4 (HCV-4) infection, initial assessment of ombitasvir + ritonavir-boosted paritaprevir+ ribavirin combination therapy for 12 weeks is based primarily on an unblinded trial in 135 patients without cirrhosis. Virological efficacy was achieved in every case. In early 2016, this combination is the peginterferon alfa-sparing antiviral regimen with the least weak evidence of virological efficacy in HCV-4 infection. In HCV-1 infection, clinical trials of this regimen combined with dasabuvir showed no improvement over the ledipasvir + sofosbuvir combination. Paritaprevir is hepatotoxic. Cases of liver failure leading to liver transplantation or death have been attributed to the ombitasvir + ritonavir-boosted paritaprevir combination, given with or without dasabuvir. This combination carries a high risk of pharmacokinetic interactions, making it very difficult to use.