Most common indications were allergic rhinitis (55%), not specified (28%), urticaria, pruritus or rash (10%) and other indications (7%). There were 40 reports of adverse drug reactions in 27 patients. Less than 2% of patients stopped the drug because of side effects. Events reported after exposure to fexofenadine were uncommon and already reported in clinical trials. There were eight reports of possible cardiac side effects (palpitations, three; chest pain, three; arrhythmia, one; and chest tightness, one). – Eur J Clin Pharmacol 2001 Jul;57(4):313-20 — Evaluation of the safety of fexofenadine from experience gained in general practice use in England in 1997. — Craig-McFeely PM, Acharya NV, Shakir SA.
Absorption of fexofenadine was reduced by 30% by consumption of grapefruit juice. The bioavailability of drugs that do not undergo significant intestinal or hepatic metabolism, such as fexofenadine, may be altered when administered with agents that influence drug transport mechanisms. – Clin Pharmacokinet 2002;41(4):311-8 — Grapefruit juice reduces the oral bioavailability of fexofenadine but not desloratadine. — Banfield C, Gupta S, Marino M, Lim J, Affrime M.
A single dose of St John’s wort significantly (P <.05) increased the maximum plasma concentration of fexofenadine by 45% and significantly (P <.05) decreased the oral clearance by 20%, with no change in half-life or renal clearance. Long-term administration of St John’s wort did not cause a significant change in fexofenadine disposition relative to the untreated phase. Compared with the single-dose treatment phase, long-term St John’s wort caused a significant 35% decrease (P <.05) in maximum plasma concentration and a significant 47% increase (P <.05) in fexofenadine oral clearance. CONCLUSIONS: A single dose of St John’s wort resulted in a significant inhibition of intestinal P-glycoprotein. Long-term treatment with St John’s wort reversed the changes in fexofenadine disposition observed with single-dose administration. – Clin Pharmacol Ther 2002 Jun;71(6):414-20 — Effect of St John’s wort on the pharmacokinetics of fexofenadine. — Wang Z, Hamman MA, Huang SM, Lesko LJ, Hall SD.
This study showed that rifampin effectively increased fexofenadine oral clearance and that this effect was independent of age and sex. We conclude that the cause of the increased oral clearance of fexofenadine is a reduced bioavailability caused by induction of intestinal P-glycoprotein. – Clin Pharmacol Ther 2001 Mar;69(3):114-21 — The effect of rifampin administration on the disposition of fexofenadine. — Hamman MA, Bruce MA, Haehner-Daniels BD, Hall SD.
Grapefruit, orange, and apple juices decreased fexofenadine absorption.Fruit juices and constituents are more potent inhibitors of OATPs than P-glycoprotein activities, which can reduce oral drug bioavailability. Results support a new model of intestinal drug absorption and mechanism of food-drug interaction. – Clin Pharmacol Ther 2002 Jan;71(1):11-20 — Fruit juices inhibit organic anion transporting polypeptide-mediated drug uptake to decrease the oral availability of fexofenadine. — Dresser GK, Bailey DG, Leake BF, Schwarz UI, Dawson PA, Freeman DJ, Kim RB.