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loratadine (Claritin)

Tradename: Claritin. (now over the counter {2002} [5,6]) Indication: - treatment of allergies - seasonal allergic rhinitis - nasal congestion, sneezing - safe during pregnancy Dosage: 1) 10 mg PO QD 2) 10 mg PO QOD if creatinine clearance < 30 mL/min 3) 10 mg PO QOD with hepatic failure Tabs: 10 mg. Claritin-D: 10 mg loratadine/240 mg pseudoephedrine sulfate. 1 tab PO QD. Claritin Reditabs: long-acting, rapidly disintegrating micronized form 10 mg PO QD Phamacokinetics: 1) onset of action: 3 hours [7] 2) take on an empty stomach - peak plasma concentrations are delayed 1 hour when taken with food 3) plasma concentrations increased by 75% in patient with chronic renal failure 4) metabolized by cyt P450 2D6 & cyt P450 3A4 5) elimination 1/2life 12-15 hours, 18 hours (geriatrics) 6) dose adjustment with liver & renal failure Adverse effects: 1) dry mouth 2) drowsiness 3) ataxia 4) headache 5) dizziness 6) does not cause prolongation of QT interval Drug interactions: 1) additive effects with other CNS depressants 2) MAO inhibitors increase anticholinergic effects 3) any pharmaceutical agent that inhibits cyt P450 2D6 or cyt P450 3A4 may increase levels of loratadine 4) any drug that induces cyt P450 3A4 may diminish levels of loratadine Laboratory: - loratadine in blood - loratadine in serum/plasma - loratadine in urine Mechanism of action: -> H1 receptor antagonist (long-acting non-sedating antihistamine)

Interactions

drug adverse effects of H1 receptor antagonists

Related

cytochrome P450 2D6 (cytochrome P450 2D, cytochrome P450 DB1, debrisoquine-4-hydroxylase, CYP2D6) cytochrome P450 3A4 (cytochrome P450 C3, nifedipine oxidase, P450-PCN1, NF-25, CYP3A4)

General

H1 receptor antagonist (antihistamine)

Properties

MISC-INFO: elimination route LIVER KIDNEY pregnancy-category B safety in lactation -

Database Correlations

PUBCHEM cid=3957

References

  1. The Pharmacological Basis of Therapeutics, 9th ed. Gilman et al, eds. Permagon Press/McGraw Hill, 1996
  2. Schering Corporation, prescribing information, 12/98
  3. Drug Information & Medication Formulary, Veterans Affairs, Central California Health Care System, 1st ed., Ravnan et al eds, 1998
  4. Prescriber's Letter 13(3): 2006 Cytochrome P450 drug interactions Detail-Document#: 220233 (subscription needed) http://www.prescribersletter.com
  5. Prescriber's Letter 9(4):24 2002
  6. Prescriber's Letter 9(12):69 2002
  7. Prescriber's Letter 15(7): 2008 Comparison of Antihistamines Detail-Document#: 240707 (subscription needed) http://www.prescribersletter.com
  8. Deprecated Reference

Component-of

loratadine/pseudoephedrine