CHAPTER 13: Cobicistat and Ritonavir as Pharmacoenhancers for Antiviral Drugs

Adherence to an active antiviral regimen, driven a by a low pill burden, convenient dosing schedule, and favorable tolerability and safety profiles, plays a critical role in the successful treatment of chronic viral infection and the prevention of resistance development. Cytochrome P450 3A (CYP3A) inhibitors ritonavir and cobicistat significantly improve the pharmacokinetic profiles of therapeutic drugs, such as the HIV protease inhibitor atazanavir and integrase inhibitor elvitegravir that are metabolized by the CYP3A, resulting in reduced pill burn, decreased dosing frequency and an improved safety profile. Both ritonavir and cobicistat have contributed to the simplification of dosing regimens and improved adherence, ensuring the successful long‐term management of HIV infection.