SUBSTANTIALLY DECREASE THE SYSTEMIC CONCENTRATIONS OF THE HIV PROTEASE INHIBITOR ATAZANAVIR, WHICH IS DEPENDENT UPON THE PRESENCE OF GASTRIC ACID FOR ABSORPTION, AND MAY RESULT IN A LOSS OF THERAPEUTIC EFFECT OF ATAZANAVIR AND THE DEVELOPMENT OF HIV RESISTANCE.IT IS THEORETICALLY POSSIBLE THAT DEXLANSOPRAZOLE MAY INTERFERE WITH THE ABSORPTION OF OTHER DRUGS WHERE GASTRIC PH IS AN IMPORTANT DETERMINANT OF ORAL BIOAVAILABILITY (E.G., AMPICILLIN ESTERS, DIGOXIN, IRON SALTS, KETOCONAZOLE).