 Cobicistat has recently been approved as an alternative booster of atazanavir at a dose of 150mg QD. It is expected that cobicistat will inhibit CYP3A mediated metabolism of daclatasvir in a similar manner as ritonavir does, but there are no clinical data to support this. As cobicistat lacks some of the adverse events associated with ritonavir use, the use of cobicistat, including as a booster of atazanavir, is likely to increase. 