• To investigate the effect at steady-state of TVR 750 mg q8h on the steady-state pharmacokinetics of escitalopram 10 mg q.d. in healthy participants and vica versa. [ Time Frame: pk profiles of TVR will be measured up to 8 hours after intake of the morning dose on Day 7 and 14 of Treatment B. Pharmacokinetic profiles of escitalopram will be measured up to 24 hours postdose on Day 7of Treatment A and Day 14 of Treatment B. ] [ Designated as safety issue: No ]
  

• The short-term safety and tolerability of coadministration of TVR and escitalopram in healthy participants [ Time Frame: This will be determined throughout the study; at all study visits ]
  

Telaprevir is being investigated for treatment of chronic HCV infection, in combination with Peg-IFN (pegylated interferon) and RBV (ribavirin). Peg-IFN plus RBV are currently an accepted methode for treating HCV. Treatment with Peg-IFN plus RBV for HCV infection is associated with a high rate of depression. The results of this study will provide dosing recommendations for coadministration of Telaprevir (TVR) and escitalopram in HCV-infected patients. This is a Phase I, open-label (both participant and investigator know the name of the medication), randomized (study medication assigned by chance), crossover trial in 16 healthy participants to investigate the pharmacokinetic interaction between escitalopram and TVR, both at steady state. Steady state is a term which means that the drug has been given long enough so that the plasma concentrations will remain the same with each subsequent dose. The participants will receive two treatments (treatment A-B or treatment B-A) in a randomized order. In Treatment A, participants will receive escitalopram 10 mg once daily (q.d.) for 7 days. In Treatment B, participants will receive TVR 750 mg every 8 hours (q8h) for 14 days, with coadministration of escitalopram 10 mg q.d. from Day 8 to Day 14. There will be a washout period (a period where no treatment will be taken in view of having all the medication eliminated from the body before starting a new treatment) of at least 14 days between last intake of study medication in one session and first intake of study medication in the subsequent session. All study medication will be taken with food. Escitalopram will be taken once daily in the morning.

During coadministration of TVR and escitalopram, the first dose of TVR should be taken together with escitalopram in the morning. Pharmacokinetic profiles of the two compounds will be measured through blood samples taken at regular intervals during the study and safety and tolerability will be assessed during the study period and in follow-up. Safety and tolerability evaluations will be recorded at regular intervals throughout the trial period.

Blood and urine samples, electrocardiogram (ECG) and vital signs (blood pressure and hart rate) will be taken at screening, before medication intake on days 1 and 7 in each session and on day 14 in treatment B and at the 2 follow up visits at 5-7 and 30-32 days after last dose of drug in the last session. A physical examination will be performed at screening, on day before first medication intake in each session and during the 2 follow up visits. Participants in Treatment A will receive oral escitalopram 10 mg once daily for 7 days and in Treatment B participants will receive TVR 750 mg q8h from Day 1 to Day 14, with coadministration of escitalopram 10 mg q.d.

from Day 8 to Day 14.