This observed increase in the bioavailability of fexofenadine may be due to transport-related effects, such as p-glycoprotein. in vivo animal studies also suggest that in addition to enhancing absorption, ketoconazole decreases fexofenadine gastrointestinal secretion, while erythromycin may also decrease biliary excretion.
<ketoconazole, mechanism, fexofenadine>