Desloratadine

What it is and how it works

Mechanism of Action Desloratadine is a long-acting tricyclic histamine antagonist with selective H 1 -receptor histamine antagonist activity. Receptor binding data indicates that at a concentration of 2-3 ng/mL (7 nanomolar), desloratadine shows significant interaction with the human histamine H 1 -receptor. Desloratadine inhibited histamine release from human mast cells in vitro . Results of a radiolabeled tissue distribution study in rats and a radioligand H 1 -receptor binding study in guinea pigs showed that desloratadine did not readily cross the blood brain barrier. The clinical significance of this finding is unknown.

Mechanism class: Histamine H1 Receptor Antagonists

Indications

Desloratadine Tablets are a histamine-1 (H1) receptor antagonist indicated for: • Seasonal Allergic Rhinitis: relief of nasal and non-nasal symptoms in patients 12 years of age and older. • Perennial Allergic Rhinitis: relief of nasal and non-nasal symptoms in patients 12 years of age and older. • Chronic Idiopathic Urticaria: symptomatic relief of pruritus, reduction in the number of hives, and size of hives in patients 12 years of age and older. Seasonal Allergic Rhinitis Desloratadine Tablets are indicated for the relief of the nasal and non-nasal symptoms of seasonal allergic rhinitis in patients 12 years of age and older. Perennial Allergic Rhinitis Desloratadine Tablets are indicated for the relief of the nasal and non-nasal symptoms of perennial allergic rhinitis in patients 12 years of age and older. Chronic Idiopathic Urticaria Desloratadine Tablets are indicated for the symptomatic relief of pruritus, reduction in the number of hives, and size of hives, in patients with chronic idiopathic urticaria 12 years of age and older.

Dosage and administration (summary)

Desloratadine Tablets may be taken without regard to meals. Dosage (by age): Adults and Adolescents 12 Years of Age and Over: • Desloratadine Tablets - one 5 mg tablet once daily Adults and Adolescents 12 Years of Age and Over The recommended dose of Desloratadine Tablets is one 5-mg tablet once daily. Adults with Hepatic or Renal Impairment In adult patients with liver or renal impairment, a starting dose of one 5 mg tablet every other day is recommended based on pharmacokinetic data. Dosing recommendation for children with liver or renal impairment cannot be made due to lack of data [ see Clinical Pharmacology ].

Contraindications

Desloratadine Tablets are contraindicated in patients who are hypersensitive to this medication or to any of its ingredients or to loratadine [ see Warnings and Precautions and Adverse Reactions ]. • Hypersensitivity ( 4 , 6.2 )

Warnings and precautions

• Hypersensitivity reactions including rash, pruritus, urticaria, edema, dyspnea, and anaphylaxis have been reported. In such cases, stop Desloratadine Tablets at once and consider alternative treatments. Hypersensitivity Reactions Hypersensitivity reactions including rash, pruritus, urticaria, edema, dyspnea, and anaphylaxis have been reported after administration of desloratadine. If such a reaction occurs, therapy with Desloratadine Tablets should be stopped and alternative treatment should be considered. [ See Adverse Reactions .]

Pregnancy

Pregnancy Risk Summary The limited available data with Desloratadine in pregnant women are not sufficient to inform a drug-associated risk for major birth defects and miscarriage. There are no adequate and well-controlled studies in pregnant women.

Storage and supply

Storage • Desloratadine Tablets: Store at 25°C (77°F); excursions permitted to 15°-30°C (59°-86°F) . Heat sensitive. Avoid exposure at or above 30°C (86°F). Dispense in a tight, light-resistant container as defined in the USP using a child-resistant closure.

Source: Desloratadine (Desloratadine) — US FDA prescribing information, 2025-07-10, DailyMed. Summarised and shortened; the full label governs. Iranian registration, indications and labelling may differ.