A Pharmacokinetic Study to Evaluate the Effect of Antacids on Raltegravir (MK-0518) in HIV-Infected Participants (MK-0518-247)

A Study to Evaluate the Effect of Metal Cation-Containing Antacids on Raltegravir Pharmacokinetics in HIV-Infected Subjects on a Stable Raltegravir-Containing Regimen

This study will evaluate: (1) the effect of co-administration of single doses of calcium carbonate antacid and magnesium/aluminum hydroxide antacid on the steady-state plasma pharmacokinetic profile of raltegravir in human immunodeficiency virus (HIV)-infected participants; and (2) the effect of staggered dosing of a single dose of a magnesium/aluminum hydroxide antacid 2 hours before and 2 hours after administration of raltegravir on the steady-state plasma pharmacokinetic profile of raltegravir in the same participants.

The study will determine whether (1) the C12hrs of steady-state raltegravir after co-administration of single doses of calcium carbonate antacid is decreased to a clinically meaningful degree compared with C12hrs after administration of raltegravir alone; and whether (2) the C12hrs of steady-state raltegravir after co-administration of a single dose of magnesium/aluminum hydroxide antacid is decreased to a clinically meaningful degree compared with the C12hrs after administration of raltegravir alone.

Inclusion Criteria:

• HIV-infected participant on a stable raltegravir dose (400 mg every 12 hours) as part of a stable anti-retroviral regimen (ARV) for at least 1 month and will maintain current ARV therapy throughout the study
• Body Mass Index ≤32 kg/m^2
• Good general health
• Can be a current smoker and/or user of nicotine or nicotine-containing products, but use of nicotine-containing products will not be permitted during the stay at the clinical research site

Exclusion Criteria:

• History of gastric bypass surgery
• Pregnant or nursing
• Mentally or legally incapacitated, has significant emotional problems, or has a history of a clinically significant psychiatric disorder; participants who have had situational depression may be enrolled at the discretion of the investigator.
• History of stroke, chronic seizures, or major neurological disorder
• History of clinically significant endocrine, gastrointestinal, cardiovascular, hematological, hepatic, immunological, renal, respiratory, or genitourinary abnormalities or diseases (excluding HIV); participants with a history of uncomplicated kidney stones or childhood asthma may be enrolled at the discretion of the investigator.
• Active neoplastic disease deemed unstable or progressing by the investigator
• Currently taking rifampin or unable to refrain from use of any proton pump inhibitor and any histamine-2 (H2)-blockers, over-the-counter antacids, calcium supplements, or multivitamins during the study
• Consumes excessive amounts of alcohol
• Consumes excessive amounts of coffee, tea, cola, or other caffeinated beverages
• Major surgery or blood donation within the past 4 weeks
• History of significant multiple and/or severe allergies or has had an anaphylactic reaction or significant intolerability to prescription or non-prescription drugs or food
• Regular user of any illicit drugs or history of drug (including alcohol) abuse within the past 6 months; current methadone or suboxone use is allowed.