Effects of Gastric pH on the Pharmacokinetics of Atazanavir

Effects of Gastric pH on the Pharmacokinetics of Atazanavir in Healthy Volunteers

The goal of this study is to evaluate the ability of a natural supplement (betaine hydrochloride) to affect the absorption of atazanavir in healthy volunteers. The investigators predict that betaine hydrochloride will increase the absorption of atazanavir in volunteers pre-treated with proton-pump inhibitors (PPIs).

Inclusion Criteria:

• Male or female 18-65 years of age
• Healthy adult with no active medical problems or significant chronic diseases as determined by the study doctor based on history, physical exam and laboratory evaluations
• BMI between 18.5-30 kg/m2
• Taking no medications 2 weeks before and during the study enrollment, including drugs of abuse, prescription or over-the-counter (OTC) medications (except acetaminophen)
• Subjects able to maintain adequate birth control during the study independent of hormonal contraceptive use
• Be able to provide written informed consent and comply with requirements of the study
• Avoid eating grapefruit and drinking grapefruit juice from 7 days before the first study day until the completion of the entire study
• Abstinence from alcoholic beverages, caffeinated beverages and orange juice from 3pm the night before a study day until completion of that study day
• Fast from food and beverages at least 8 hours prior to medication dosing
• Be able to read, speak, and understand English

Exclusion Criteria:

• Subjects with a history of gastrointestinal disease including gastroesophageal reflux disease, gastritis, peptic ulcer disease, or dyspepsia
• Subjects with a fasting gastric pH of > 4 (i.e. hypochlorhydria)
• Subjects with a history of dysphagia, achalasia, or difficulty swallowing capsules, tablets, or pills
• Subjects on prescription or chronic over-the-counter (OTC) medications (including hormonal contraceptives)
• Subjects with known allergies rabeprazole, any other proton pump inhibitors (PPI's) or betaine hydrochloride
• Subjects who smoke tobacco
• Subjects with ongoing alcohol or illegal drug use
• Subjects who are pregnant, lactating, or attempting to conceive
• Subjects unable to maintain adequate birth control during the study