Study to Characterize the Pharmacokinetics of Raltegravir in the Gastrointestinal (GI) Tract of Healthy Male Volunteers

Participants: 14 HIV-uninfected, healthy, male volunteers, ≥18 and ≤49 years of age, will be recruited and enrolled. Healthy is defined as no clinically relevant abnormalities identified by a detailed medical history, full physical examination, including blood pressure and pulse rate measurement, 12-lead ECG, and clinical laboratory tests. Participants of all races and ethnicities will be considered for enrollment. This study will be conducted at a single site in the United States: the University of North Carolina at Chapel Hill. Procedures (methods): An outpatient screening visit will be conducted on all potential participants to obtain informed consent and evaluate for eligibility. Once enrolled, all subjects will take 400 mg oral dose of raltegravir twice daily from Day 1 to Day 7. The healthy men enrolled in this study will undergo single-dose and multiple-dose pharmacokinetic sampling. Blood will be collected via peripheral IV at pre-dose, and at 1, 2, 3, 4, 6, 8 and 12 hours post-dose. Subjects will undergo two colonoscopies during sampling visits (Day 1 and Day 7) for the purpose of obtaining gastrointestinal-associated lymphoid tissue (GALT). Each subject will have his biopsy obtained at one of the following time points post-dose: 1, 2, 3, 4, 6, 8, and 12 hours. Seven to ten days after their last inpatient sampling visit, all subjects will complete a follow-up visit.