 The purpose of this study is to investigate the effect of steady-state concentrations of erythromycin or DRVr on the steady-state pharmacokinetics of TMC435, the effect of a steady-state concentration of TMC435 150 mg on the steady-state pharmacokinetics of erythromycin and the effect of a steady-state concentration of TMC435 50 mg on the steady-state pharmacokinetics of DRVr. We will also study the short-term safety and tolerability of TMC435 given alone and given togehter with erythromycin Panel 1 or DRVr Panel 2. Steady state is a term that means that the drug has been given long enough so that the plasma concentrations will remain the same with each subsequent dose. TMC435 is being investigated for the treatment of chronic hepatitis C virus HCV infection. Pharmacokinetics PK means how the drug is absorbed into the bloodstream, distributed in the body, and eliminated from the body. 