Loratadine


Description

Loratadine is a second generation antihistamine used to manage symptoms of allergic rhinitis.[

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Pharmacology

Indication

Loratadine is a 2nd generation antihistamine and is used to manage symptoms of allergic rhinitis, wh... Read more

Pharmacodynamic

Like other 2nd generation antihistamines, loratadine is selective for peripheral H1 receptors.[ Read more

Mechanism of action

Histamine release is a key mediator in allergic rhinitis and urticaria.[ Read more

Absorption

Loratadine is rapidly absorbed and achieves peak plasma concentration in 1-2 hours, while it's main... Read more

Protein binding

97 - 99% of the loratadine is bound to plasma proteins.[ Read more

Volume of distribution

The volume of distribution of loratadine is 120 L/Kg.[ Read more

Clearance

The clearance of loratadine after single oral doses of 20 mg and 40 mg are 12 L/h/kg and 9 L/h/kg re... Read more

Half life

The elimination half life is approximately 10 hours for loratadine and 20 hours for descarboethoxylo... Read more

Route of elimination

Over a 10 day period, 40% of loratadine is excreted in the urine, and 42% is eliminated in the faece... Read more

Toxicity

Second generation antihistamines such as loratadine have very few adverse effects; however, insomnia... Read more


Adverse Effects

Effect Regions Age Groups Incidences Evidence Type
Headache US
  • Kind: experimental
    • Percent: 12
  • Somnolence/fatigue US
  • Kind: experimental
    • Percent: 8
  • Fatigue Symptom US
  • Kind: experimental
    • Percent: 4
  • Wheezing US
  • Kind: experimental
    • Percent: 4
  • Nervousness US
  • Kind: experimental
    • Percent: 4
  • Hyperkinesia US
  • Kind: experimental
    • Percent: 3
  • General fatigue US
  • Kind: experimental
    • Percent: 3
  • Dry Mouth US
  • Kind: experimental
    • Percent: 3
  • Malaise US
  • Kind: experimental
    • Percent: 2
  • Upper Respiratory Tract Infection US
  • Kind: experimental
    • Percent: 2
  • Dysphonia US
  • Kind: experimental
    • Percent: 2
  • Conjunctivitis US
  • Kind: experimental
    • Percent: 2
  • Abdominal Pain US
  • Kind: experimental
    • Percent: 2

  • Contraindications

    • Route:
      • Oral
    • Dose Form:
      • Liquid
      • Tablet
      • Tablet, orally disintegrating
    • Regions: US
    • Patient Conditions:
        • Name: Hypersensitivity Reaction
        • Drugbank Id: DBCOND0053862

    Food Interactions

    • Take on empty stomach: 1 hour before or 2 hours after meals.

    Interactions

    Type in a drug name to check for interaction with Loratadine

    The metabolism of (R)-warfarin can be increased when combined with Loratadine.
    The metabolism of (S)-Warfarin can be increased when combined with Loratadine.
    The metabolism of Loratadine can be decreased when combined with 1-(2-Phenylethyl)-4-phenyl-4-acetoxypiperidine.
    2,5-Dimethoxy-4-ethylamphetamine may decrease the sedative and stimulatory activities of Loratadine.
    2,5-Dimethoxy-4-ethylthioamphetamine may decrease the sedative and stimulatory activities of Loratadine.
    The metabolism of 3,5-diiodothyropropionic acid can be increased when combined with Loratadine.
    4-Bromo-2,5-dimethoxyamphetamine may decrease the sedative and stimulatory activities of Loratadine.
    The metabolism of 4-hydroxycoumarin can be increased when combined with Loratadine.
    The metabolism of 4-Methoxyamphetamine can be decreased when combined with Loratadine.
    The metabolism of 5-androstenedione can be increased when combined with Loratadine.
    The metabolism of 5-methoxy-N,N-dimethyltryptamine can be decreased when combined with Loratadine.
    The metabolism of Loratadine can be decreased when combined with 6-Deoxyerythronolide B.
    The metabolism of 6-O-benzylguanine can be increased when combined with Loratadine.
    The metabolism of 7-ethyl-10-hydroxycamptothecin can be increased when combined with Loratadine.
    The metabolism of 8-azaguanine can be decreased when combined with Loratadine.
    The metabolism of 8-chlorotheophylline can be decreased when combined with Loratadine.
    The metabolism of 9-aminocamptothecin can be increased when combined with Loratadine.
    The metabolism of 9-Deazaguanine can be decreased when combined with Loratadine.
    The metabolism of 9-Methylguanine can be decreased when combined with Loratadine.
    The metabolism of Loratadine can be increased when combined with Abatacept.

    References

    • 1 . See S: Desloratadine for allergic rhinitis. Am Fam Physician. 2003 Nov 15;68(10):2015-6. [PubMed: 14655812]
    • 2 . Menardo JL, Horak F, Danzig MR, Czarlewski W: A review of loratadine in the treatment of patients with allergic bronchial asthma. Clin Ther. 1997 Nov-Dec;19(6):1278-93; discussion 1523-4. [PubMed: 9444440]
    • 3 . Howarth PH: Histamine and asthma: an appraisal based on specific H1-receptor antagonism. Clin Exp Allergy. 1990 Aug;20 Suppl 2:31-41. [PubMed: 1977506]
    • 4 . Baroody FM, Naclerio RM: Antiallergic effects of H1-receptor antagonists. Allergy. 2000;55 Suppl 64:17-27. [PubMed: 11291777]
    • 5 . Tenn MW, Steacy LM, Ng CC, Ellis AK: Onset of action for loratadine tablets for the symptomatic control of seasonal allergic rhinitis in adults challenged with ragweed pollen in the Environmental Exposure Unit: a post hoc analysis of total symptom score. Allergy Asthma Clin Immunol. 2018 Jan 16;14:5. doi: 10.1186/s13223-017-0227-4. eCollection 2018. [PubMed: 29371864]
    • 6 . Barenholtz HA, McLeod DC: Loratadine: a nonsedating antihistamine with once-daily dosing. DICP. 1989 Jun;23(6):445-50. [PubMed: 2525847]
    • 7 . Randall KL, Hawkins CA: Antihistamines and allergy. Aust Prescr. 2018 Apr;41(2):41-45. doi: 10.18773/austprescr.2018.013. Epub 2018 Apr 3. [PubMed: 29670310]
    • 8 . Church MK, Church DS: Pharmacology of antihistamines. Indian J Dermatol. 2013 May;58(3):219-24. doi: 10.4103/0019-5154.110832. [PubMed: 23723474]
    • 9 . Clissold SP, Sorkin EM, Goa KL: Loratadine. A preliminary review of its pharmacodynamic properties and therapeutic efficacy. Drugs. 1989 Jan;37(1):42-57. [PubMed: 2523301]
    • 10 . Ghosal A, Gupta S, Ramanathan R, Yuan Y, Lu X, Su AD, Alvarez N, Zbaida S, Chowdhury SK, Alton KB: Metabolism of loratadine and further characterization of its in vitro metabolites. Drug Metab Lett. 2009 Aug;3(3):162-70. Epub 2009 Aug 1. [PubMed: 19702548]
    • 11 . Zhang YF, Chen XY, Zhong DF, Dong YM: Pharmacokinetics of loratadine and its active metabolite descarboethoxyloratadine in healthy Chinese subjects. Acta Pharmacol Sin. 2003 Jul;24(7):715-8. [PubMed: 12852841]
    • 12 . Naclerio RM: The role of histamine in allergic rhinitis. J Allergy Clin Immunol. 1990 Oct;86(4 Pt 2):628-32. doi: 10.1016/s0091-6749(05)80227-1. [PubMed: 1977783]
    • 13 . Obradovic T, Dobson GG, Shingaki T, Kungu T, Hidalgo IJ: Assessment of the first and second generation antihistamines brain penetration and role of P-glycoprotein. Pharm Res. 2007 Feb;24(2):318-27. doi: 10.1007/s11095-006-9149-4. Epub 2006 Dec 19. [PubMed: 17180728]
    • 14 . Conen S, Theunissen EL, Vermeeren A, van Ruitenbeek P, Stiers P, Mehta MA, Toennes SW, Ramaekers JG: The role of P-glycoprotein in CNS antihistamine effects. Psychopharmacology (Berl). 2013 Sep;229(1):9-19. doi: 10.1007/s00213-013-3075-z. Epub 2013 Apr 7. [PubMed: 23564211]
    • 15 . Kazmi F, Barbara JE, Yerino P, Parkinson A: A long-standing mystery solved: the formation of 3-hydroxydesloratadine is catalyzed by CYP2C8 but prior glucuronidation of desloratadine by UDP-glucuronosyltransferase 2B10 is an obligatory requirement. Drug Metab Dispos. 2015 Apr;43(4):523-33. doi: 10.1124/dmd.114.062620. Epub 2015 Jan 16. [PubMed: 25595597]
    • 16 . Aratyn-Schaus Y, Ramanathan R: Advances in high-resolution MS and hepatocyte models solve a long-standing metabolism challenge: the loratadine story. Bioanalysis. 2016 Aug;8(16):1645-62. doi: 10.4155/bio-2016-0094. Epub 2016 Jul 27. [PubMed: 27460981]
    • 17 . Claritin Product Monograph [Link]
    • 18 . Comparative Pharmacology of the H1 Antihistamines [Link]
    • 19 . Claritin Product Information [Link]

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