Age 18 to 65 years.
Healthy by medical history and physical exam.
No concurrent chronic medications, including oral contraceptives.
Non-smoker or not having smoked for the past 6 months or longer.
Laboratory values within established NIAID guidelines for participation in clinical studies: AST/SGOT less than or equal to 2 times ULN; Serum creatinine less then or equal to ULN; Hemoglobin greater than or equal to 10 g/dl.
Ability to abstain from caffeine containing foods/beverages, ethanol, grapefruit or grapefruit juice and charbroiled foods for 72 hours prior to, and the day of, phenotyping procedures.
Ability to abstain from dextromethorphan-containing over the counter preparations for 72 hours prior to, and the day of, phenotyping procedures.
No concomitant therapy with other inhibitors or inducers of cytochrome P-450 mediated drug metabolism within 30 days of study (including grapefruit juice).
No ingestion of dietary supplements within the past 30 days.
Ability to obtain venous access for sample collection.
No presence of life-threatening or unstable renal, hepatic, cardiovascular, hematologic, neurologic, psychiatric, or respiratory disease or any other condition that may interfere with the interpretation of the study results or not be in the best interests of the patient in the opinion of the investigator.
Patients must not have a positive pregnancy test.
No presence of persistent diarrhea or malabsorption that would interfere with the patient's ability to adequately absorb drugs.
No drug or alcohol use that may impair safety or adherence.
No history of intolerance to milk thistle, indinavir, caffeine, or dextromethorphan preparations.