Note: this interaction was studied using a darunavir/ritonavir dose lower than that licensed. Coadministration increases atorvastatin concentrations. Coadministration of atorvastatin (10 mg once daily) and darunavir/ritonavir (300/100 mg twice daily) resulted in atorvastatin exposure that was only 15% lower than that obtained with atorvastatin 40 mg once daily alone. When coadministered it is recommended to start with atorvastatin 10 mg once daily. A gradual dose increase may be tailored to the clinical response. A daily dose of 40 mg atorvastatin should not be exceeded with careful safety monitoring. (Note, the US product label for Prezista states not to exceed atorvastatin 20 mg/day.)