The purpose of this study is to determine the effect of EFV (Efavirenz) and TDF (Tenofovir disoproxil fumarate) on the pharmacokinetics of TVR (Telaprevir) and to determine the effect of TVR on the pharmacokinetics of EFV and TDF. Pharmacokinetics means how the drug is absorbed into the bloodstream, distributed in the body and eliminated from the body. Furthermore, the short-term safety and tolerability of giving TVR, EFV and TDF together will be evaluated.