levocetirizine dihydrochloride
Levocetirizine is an antihistamine that selectively blocks H₁ receptors, reducing the effects of histamine to relieve allergy and urticaria symptoms.
Used for the relief of symptoms of seasonal and perennial allergic rhinitis, and the treatment of chronic idiopathic urticaria in adults and children.
Adults and children ≥12 years: 5 mg once daily in the evening.
Children 6–11 years: 2.5 mg once daily.
Children 6 months–5 years: 1.25 mg once daily.
Dose adjustments required for renal impairment.
Common side effects include somnolence, nasopharyngitis, fatigue, dry mouth, and pharyngitis. In younger children, pyrexia, cough, vomiting, diarrhea, and otitis media may occur.
Contraindicated in patients with known hypersensitivity to levocetirizine, cetirizine, or any of the formulation components; also in patients with end-stage renal disease and pediatric patients with renal impairment.
May cause drowsiness and affect mental alertness; caution is advised when operating machinery or driving. Avoid alcohol and CNS depressants due to additive sedation.
Levocetirizine dihydrochloride is the active R-enantiomer of cetirizine, formulated as a 5 mg immediate-release tablet or 0.5 mg/mL oral solution, used as a non-sedating antihistamine for allergic conditions.