Darunavir/ritonavir is indicated in combination with other antiretroviral drugs for the treatment of HIV-1 infection in pre-treated adult patients. In hepatitis B or C co-infected patients, the virological response rate to darunavir/ritonavir appeared to be unaffected and, except for increased liver enzymes, the incidence of adverse events was not higher than in patients without co-infection. Drug-induced hepatitis has been reported in 0.5% of patients receiving combination therapy with darunavir/ritonavir. Patients with pre-existing liver dysfunction, including chronic active hepatitis B or C, have an increased risk for liver function abnormalities including severe hepatic adverse events. Therefore AST/ALT monitoring should be considered in patients with underlying chronic hepatitis, (HVB/HCV) like it is recommended in all patients receiving boosted PIS. Darunavir is primarily metabolized by the liver. The steady-state pharmacokinetic parameters of darunavir are similar in patients with normal liver function, mild hepatic impairment (Child-Pugh Class A), and moderate hepatic impairment (Child-Pugh Class B). The effect of severe hepatic impairment on the pharmacokinetics of darunavir has not been evaluated. No dose adjustment is required in patients with mild or moderate hepatic impairment. There are no data on the use of darunavir in patients with severe hepatic impairment and consequently this drug is not recommended in this group of patients.