A Study to Evaluate the Pharmacokinetic Effect of SCH 503034 (Boceprevir) on Methadone or Buprenorphine/Naloxone Plasma Concentrations (P08123)

Inclusion Criteria: * Body Mass Index (BMI) between 18 and 36, inclusive * Reliable participation in a methadone maintenance or buprenorphine maintenance or buprenorphine/naloxone maintenance program for at least two (2) months prior to Day 1. * Is receiving once daily oral dose of methadone therapy at a stable individualized dose for at least 4 weeks, receiving once daily buprenorphine dose at a stable individualized dose for at 4 weeks with, if on buprenorphine only therapy, naloxone added for at least 2 weeks prior to Day 1. * 12-lead electrocardiogram (ECG) conduction intervals within gender-specific normal range * Vital signs within normal range * Clinical laboratory tests within normal range * Women who are postmenopausal, surgically sterilized, or premenopausal and use a medically-accepted method of contraception. Exclusion Criteria: * Pregnancy, breast feeding, or intention to become pregnant or father a child while on study or within 3 months after end of trial * History or presence of inflammatory bowel disease, ulcers, or gastrointestinal or rectal bleeding * History of major gastrointestinal tract surgery such as gastrectomy, gastroenterostomy, or bowel resection * History of pancreatic injury or pancreatitis * History or presence of liver disease or liver injury * History or presence of impaired renal function * History of urinary obstruction or difficulty in voiding * History of any infectious disease within 4 weeks prior to drug administration that in the opinion of the investigator, affects the subject's ability to participate in the trial * Positive for hepatitis B surface antigen, hepatitis C antibodies or human immunodeficiency virus (HIV) * Positive screen for drugs with a high potential for abuse such as cocaine, amphetamines, methylenedioxymethamphetamine (MDMA), barbiturates, benzodiazepines, or opiates/opioids * Excessive use of alcohol in the 2 weeks prior to Day -1, defined as greater than 3 glasses of alcoholic beverages (1 is approximately equivalent to: beer \[284 mL/10 oz\], wine \[125 mL/4 oz\], or distilled spirits \[25 mL/1 oz\]) per day. * Blood donation in the past 60 days * Previous administration of SCH 503034 (boceprevir) * Current participation in another clinical study or participation in a clinical study (e.g., laboratory or clinical evaluation) within 30 days of baseline * Study staff personnel or family members of the study staff personnel * Demonstrated allergic reactions (eg, food, drug, atopic reactions or asthmatic episodes) that, in the opinion of the investigator and sponsor, interfere with their ability to participate in the trial * History of malignancy within 5 years from Screening * Consumption of excessive amounts (equivalent to \> 6 cups of brewed coffee/day) of coffee, tea, cola or other caffeinated beverages * Receipt of any of the following more recently than the washout period prior to Baseline: inhibitors or inducers of cytochrome (CYP) P450, CYP2B6, CYP3A4, and CYP2D6; or oral contraceptives containing drospirenone