phenobarbital will minimize the extent or effect of ombitasvir/paritaprevir/ritonavir & dasabuvir (DSC) by impacting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated. Potent CYP3A4 inducers might decrease partiaprevir and ritonavir ranges, and so reduced efficacy of Viekira Pak ph