The Effect of Intermittent Rifampicin on Raltegravir

Inclusion Criteria: * The ability to understand and sign a written informed consent form, prior to participation in any screening procedures and must be willing to comply with all study requirements. * ≥ 18 years * Male or female subjects * A female may be eligible to enter and participate in the study if she: * Is of non-child-bearing potential defined as ether post-menopausal (12 months of spontaneous amenorrhea and ≥ 45 years of age)or physically incapable of becoming pregnant with documented tubal ligation, hysterectomy or bilateral oophorectomy or * Is of child-bearing potential with a negative pregnancy test at screening and agrees to use one of the following methods of contraception to avoid pregnancy * Complete abstinence from intercourse from 2 weeks prior to administration of IP, throughout the study and for at least 4 weeks after discontinuation of all study medication * Double barrier method (male condom/spermicide, male condom/diaphragm, diaphragm/spermicide) * Any intrauterine device (IUD) with published data showing that the expected failure rate is \< 1 % per year * Any other method with published data showing that the expected failure rate is \< 1 % PER YEAR * Hormonal contraception plus a barrier method. Hormonal contraception alone will not be considered adequate for inclusion into or participation in this study due to one of the study drugs being rifampicin. All subjects participating in the study will be counseled on safer sexual practices including the use of effective barrier methods (e.g. male condom) Exclusion Criteria: * Any significant acute or chronic medical condition * Pregnant or lactating women * Women of childbearing age unless using non hormonal contraception * Males who are not using contraception * Evidence of organ dysfunction or any clinically significant deviation from normal during screening including laboratory determinations such as abnormal LFTs * Positive blood screen for HIV-1 and 2 antibodies * Positive blood screen for hepatitis B or C antibodies * Positive IGRA screen for TB * Current or recent (within 3 months) gastrointestinal disease * Clinically relevant alcohol or drug use or history of alcohol or drug use that will hinder compliance with treatment, follow up procedures or evaluation of adverse effects * Use of proton pump inhibitors * Exposure to any investigational drug or placebo within 4 weeks of first dose of study drug * Consumption of grapefruit and Seville oranges or products containing grapefruit or Seville oranges within 1 week of first study drug and for the duration of the study * Use of any other drugs including over-the-counter medications and herbal preparations, within 2 weeks prior to first dose of study drug * Previous allergy to any of the constituents of the pharmaceuticals in this trial