The incidence of co-infection with HIV and hepatitis C virus (HCV) in IDUs is high. An estimated 50-90% of IDUs in the U.S. are co-infected with HIV/Hepatitis C according to the Center for Disease Control and Prevention. HIV co-infection aggravates the natural course of HCV infection. In a meta-analysis of the effect of HIV on the progression of HCV liver disease compared to mono-infection with HCV, the relative risk of end-stage liver disease (ESLD) and cirrhosis with HIV co-infection was found to be 6.14 and 2.07, respectively. Difficulties arise in the treatment of HIV with respect to HCV liver disease. Drug hepatotoxicity is a major concern in the selection of an appropriate antiretroviral regimen. Optimising therapy in this patient group necessitates a balance between retroviral suppression and minimising hepatic side effects.