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fexofenadine (Allegra)

Tradename: Allegra. (fexofenadine HCl) Empirical formula: C32H39NO4*HCl. Indication: - seasonal allergic rhinitis in adults & children > 12 years of age - allergic conjunctivitis - urticaria Dosage: 60 mg PO BID. Tabs: 60 mg. Pharmacokinetics: 1) onset of action 3 hours [5] 2) negligible (5%) metabolism 3) active metabolite of terfenadine 5) bioavailability [3] a) absorption dependent upon an anion transporter, organic anion transporting polypeptide (OATP) [6] b) absorption inhibited up to 70% when taken with fruit juice [6] (orange juce, grapefruit juice) 6) elimination 80% in feces, 11% in urine 7) 1/2life 14.4 hours - 21 hours with creatinine clearance 40-80 mL/min - 25 hours with creatinine clearance 10-40 mL/min 8) protein binding 60-70% - binds to albumin, alpha-1 acid glycoprotein Dosage adjustment in renal failure: - 60 mg QD for creatinine clearance < 80 mg/dL Adverse effects: (uncommon) 1) flu-like symptoms (2.5%) 2) nausea (1.5%) 3) dysmenorrhea (1.5%) 4) drowsiness (1.3%) 5) dyspepsia (1.3%) 6) fatigue (1.3%) 7) no prolongation of QT interval Drug interactions: -> erythromycin & ketoconazole increase fexofenadine levels, but (up to 80%) but not associated with increased incidence of adverse effects Laboratory: - fexofenadine in blood - fexofenadine in serum/plasma - fexofenadine in urine

Interactions

drug adverse effects of H1 receptor antagonists

General

H1 receptor antagonist (antihistamine)

Properties

SIZE: MW = 538 G/M MISC-INFO: 1/2life 14 HOURS elimination route LIVER KIDNEY elimination by hemodialysis - pregnancy-category C safety in lactation -

Database Correlations

PUBCHEM correlations

References

  1. Hoest Marion Roussel
  2. Mayo Internal Medicine Board Review, 1998-99, Prakash UBS (ed) Lippincott-Raven, Philadelphia, 1998, pg 34
  3. Kaiser Permanente Northern California Regional Drug Formulary, 1998
  4. Prescriber's Letter 8(6):33 2001
  5. Prescriber's Letter 15(7): 2008 Comparison of Antihistamines Detail-Document#: 240707 (subscription needed) http://www.prescribersletter.com
  6. Prescriber's Letter 18(6): 2011 OATP Fruit Juice Drug Interactions Detail-Document#: 270602 (subscription needed) http://www.prescribersletter.com

Component-of

fexofenadine/pseudoephedrine (Allegra-D)