A Drug Interaction Study Investigating the Effect of Rifabutin on the Pharmacokinetics of Maraviroc

Inclusion Criteria: * Able and willing to sign informed consent prior to any study-related activities. * Male or female participants between 18 and 65 years of age inclusive. * Body Mass Index (BMI) of 17.5 to 30.5 kg/m2; and a total body weight \>50 kg (110 lbs). * Healthy, i.e. not suffering from an acute or chronic illness and not using medications. * Acceptable medical history, physical examination, and 12-lead ECG at screening. * Acceptable laboratory values that indicate adequate baseline organ function at screening visit. * Willing to stop using any herbal or natural health products for 2 weeks prior to and during the study including: Grapefruit, grapefruit juice, St. John's Wort. * Willingness to abstain from alcohol use for 3 days prior to and during the study. * Participant must practice a reliable method of birth control while they are participating in the study; for instance an intrauterine device (IUD), condom with spermicidal gel or foam, diaphragm with spermicidal gel or foam, vasectomy, tubal ligation, hysterectomy or abstinence or female must be post menopausal for at least one year. Exclusion Criteria: * Have serological evidence of exposure to HIV * Female patients of childbearing potential who has a positive urine pregnancy test at screening * Participants not willing to use a reliable method of barrier contraception during the study. * Is breastfeeding. * Inability to adhere to protocol. * Use of any medications (2 weeks prior to or during the study) other than occasional use of acetaminophen. * Participants taking oral contraceptive medications. * Any condition possibly affecting drug absorption (eg, gastrectomy). * Patients may be excluded from the study for other reasons, at the investigator's discretion.