Coadministration with rifaximin has not been studied but there is a low potential for interaction. In vitro studies suggest that rifaximin is a substrate of CYP3A4, P-gp, and OATP1, as well as a weak inducer of CYP3A4 and weak inhibitor of P-gp. Concentrations of rifaximin may increase due to inhibition of P-gp by ledipasvir but the clinical significance of this is unclear as systemic absorption of rifaximin is minimal.