Clarinex, Clarinex Reditabs
Classifications: antihistamine, nonsedating; h1-receptor antagonist;
; h1-receptor antagonist; antiallergic
Prototype: Loratadine
Pregnancy Category: C


5 mg tablets; 2.5 mg, 5 mg orally dissolving tablets; 0.5 mg/mL syrup


A long-acting, nonsedating antihistamine with selective H1-receptor antagonist properties. The drug reduces human mast cell release of the inflammatory cytokines. Therefore, it also exhibits antiallergic effects. It is more potent than loratadine as an antagonist at H1-receptors.

Therapeutic Effect

Desloratadine is effective in controlling allergic rhinitis and inhibiting histamine-induced wheals and flare (hives).


Treatment of seasonal or perennial allergic rhinitis and idiopathic urticaria.


Hypersensitivity to desloratadine or loratadine; neonates; infants; pregnancy (category C); lactation.

Cautious Use

Renal and hepatic insufficiencies; bladder neck obstruction or urinary retention; prostatic hypertrophy; asthma; glaucoma. Safety and efficacy in children <12 y not known.

Route & Dosage

Allergic Rhinitis, Idiopathic Urticaria
Adult: PO 5 mg q.d.

Renal Impairment
Adult: PO Clcr <50 mL/min: 5 mg every other day

Hepatic Impairment
Adult: PO 5 mg every other day


  • Note that drug should be given q.o.d. to patients with significant renal or hepatic impairment.
  • Store between 2°–25° C (36°–77° F).

Adverse Effects (≥1%)

Body as a Whole: Pharyngitis, fatigue, flu-like symptoms, myalgia. CNS: Somnolence, dizziness. GI: Dry mouth, nausea, dry throat. Urogenital: Dysmenorrhea.


Drug: No clinically significant interactions established.


Absorption: Well absorbed. Peak: 3 h. Distribution: 85–89% protein bound. Metabolism: Extensively metabolized in liver to 3-hydroxydesloratadine, an active metabolite. Elimination: Equally in urine and feces. Half-Life: 27 h.

Nursing Implications

Assessment & Drug Effects

  • Assess carefully for and report distressing or dangerous S&S that occur after initiation of the drug. a variety of adverse effects, although not common, are possible. Some are an indication to discontinue the drug.
  • Monitor cardiovascular status and report significant changes in BP and palpitations or tachycardia.
  • Lab tests: Monitor periodically renal and liver function tests.
  • Concurrent drugs: Monitor ECG when used in combination with any other drug that can increase blood level of desloratidine in patients with preexisting cardiac disease.

Patient & Family Education

  • Drug may cause significant drowsiness in older adult patients and those with liver or kidney impairment.
  • Note: Concurrent use of alcohol and other CNS depressants may have an additive effect.
  • Do not take this drug more often than every other day if you have renal impairment.

Common adverse effects in italic, life-threatening effects underlined; generic names in bold; classifications in SMALL CAPS; Canadian drug name; Prototype drug

© 2006-2022 Last Updated On: 11/20/2022 (0)
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