Fexofenadine Apple juice

Grapefruit juice raises terfenadine ievels, increasing the risk of QT interval prolongation and torsade de pointes arrhythmias. Grapefruit juice does not appear to alter the pharmacokinetics of astemizole and desloratadine. The absorption of fexofenadine is modestly reduced by grapefruit juice, orange juice and apple juice. 

Further study is required to determine the clinical relevance, if any, of the reductions in fexofenadine bioavailability in the presence of grapefruit juice, orange juice, and apple juice. Consider this interaction as the cause if fexofenadine seems less effective than expected. 

Certain fruit juices (ie, apple, orange, grapefruit) administered with fexofenadine significantly reduced the AUC and C ax of fexofenadine. Therefore, fexofenadine s... 

Fruit juices such as grapefruit, orange, and apple may reduce the bioavailability and exposure of fexofenadine. This is based on the results from three clinical studies using histamine-induced skin wheals and flares coupled with population pharmacokinetic analysis. Therefore, to maximize the effects of fexofenadine, it is recommended that ALLEGRA-D 24 HOUR should be taken with water... 

Fexofenadine and digoxin are both well-known substrates for OATP transport, though the relative contribution of OATP modulation on drug interactions involving these two agents is unclear, since both are also P-gp substrates. The 60-80% reduction in fexofenadine bioavailability that results from orange, apple, and grapefruit juice consumption, however, is likely the result of OATP inhibition, rather than of P-gp induction (94). 

The components of grapefruit Juice reportedly inhibit P-gp, and this may be one of the mechanisms for the increase in bioavailability of drugs that are substrates for P-gp (Table 10.16). Although fexofenadine is a P-gp substrate, rather than a decrease in its plasma levels when it is coadministered with grapefruit Juice, the blood levels are increased as a result of fexofenadine being a substrate of the anion transporter (OATP) in the intestine. Studies have shown that apple and other fruit Juices are more potent inhibitors of OATP than of P-gp. 

Fexofenadine is a substrate for P-glycoprotein, and organie anion transporting polypeptide (OATP), both of which affect fexofenadine uptake. OATP in particular may be inhibited by grapefruit juice, apple juiee, and orange juice, so these juices may reduce fexofenadine levels by preventing its absorption. ... 

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