Overview
Desloratadine is a second-generation antihistamine used for symptomatic relief of allergic conditions. It selectively blocks peripheral H1 receptors, providing 24-hour relief from symptoms like rhinorrhea, sneezing, and itchy eyes with minimal sedation. The drug is typically administered once daily and is available in various oral formulations.
Mechanism of Action
Desloratadine is a long-acting tricyclic antihistamine with selective peripheral histamine H1-receptor antagonist activity. It inhibits histamine release from mast cells and reduces expression of adhesion molecules involved in allergic inflammation, providing sustained relief from allergic symptoms.
Indications
- Relief of nasal and non-nasal symptoms of seasonal allergic rhinitis
- Symptomatic treatment of perennial allergic rhinitis
- Chronic idiopathic urticaria
Common Doses
- 5 mg tablet
- 0.5 mg/mL oral solution
- 2.5 mg/5 mL oral solution
- 5 mg orally disintegrating tablet
Dosage
Adults and adolescents 12 years and older: 5 mg once daily. May be taken with or without food. Dosage adjustment may be required in patients with renal or hepatic impairment.
Contraindications
- Hypersensitivity to desloratadine, loratadine, or any component of the formulation
Side Effects
- Headache
- Dry mouth
- Fatigue
- Somnolence
- Pharyngitis
- Nausea
- Dizziness
Interactions
- Erythromycin and ketoconazole may increase desloratadine plasma concentrations
- Alcohol may enhance CNS depressant effects
- No clinically significant interactions with azithromycin, fluoxetine, or cimetidine
Counseling Points
- Take once daily as prescribed, with or without food
- May cause drowsiness - avoid alcohol and use caution when driving
- Store at room temperature away from moisture
- Do not crush or chew orally disintegrating tablets
- Report any unusual heart rhythm symptoms to healthcare provider