Absorption of azole antifungal agents are affected by the gastric pH. A low pH is needed for adequate dissolution and absorption of the drug. A patient with a hypochlorhydria or achlorhydria may have inadequate oral absorption.
Azoles that may have reduced absorption if gastric pH is too high:
(1) itraconazole
(2) ketoconazole
Clinical findings of decreased absorption due to elevated gastric pH:
(1) poor clinical response or lower than expected serum levels
(2) exclusion of noncompliance and drug resistance