A Two Way Cross Over Pharmacokinetic Interaction Study Between Raltegravir and Amlodipine in Healthy Volunteers

Inclusion Criteria: Subjects must meet all of the following inclusion criteria within 28 days prior to the baseline visit: * 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 * Male or non-pregnant, non-lactating females * Between 18 to 65 years, inclusive * Body Mass Index (BMI) of 18 to 35 kg/m2, inclusive. * Women of childbearing potential (WOCBP) must be using an adequate method of contraception to avoid pregnancy throughout the study and for a period of at least 12 weeks after the study * Willing to consent to their personal details being entered onto The Over-volunteering Prevention Scheme (TOPS) database * Willing to provide photographic identification at each visit. * Registered with a GP in the UK Exclusion Criteria: Subjects who meet any of the following exclusion criteria are not to be enrolled in this study. * Any significant acute or chronic medical illness including hypertension (BP persistently \>140/90 mmHg) or hypotension (BP persistently \<90/60 mmHg) * Evidence of organ dysfunction or any clinically significant deviation from normal in physical examination, vital signs, ECG or clinical laboratory determinations * Positive blood screen for hepatitis B surface antigen and/or C antibodies * Positive blood screen for HIV-1 and/or 2 antibodies * Current or recent (within 3 months) gastrointestinal disease * Clinically relevant alcohol or drug use (positive urine drug screen) or history of alcohol or drug use considered by the Investigator to be sufficient to hinder compliance with treatment, follow-up procedures or evaluation of adverse events. Smoking is permitted, but tobacco intake should remain consistent throughout the study * Exposure to any investigational drug or placebo within 3 months of first dose of study drug * Use of any other drugs (unless approved by the Investigator), including over-the-counter medications and herbal preparations, within two weeks prior to first dose of study drug, unless approved/prescribed by the Principal Investigator as known not to interact with study drugs. * Females of childbearing potential without the use of effective non-hormonal birth control methods, or not willing to continue practising these birth control methods for at least 12 weeks after the end of the treatment period * Previous allergy to any of the constituents of the pharmaceuticals administered in this trial * Lactose intolerance