Effects of Gastric pH on the Pharmacokinetics of Atazanavir

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