Levocetirizine

Class: Second-generation antihistamine (H1-receptor antagonist), active enantiomer of cetirizine

Indications: Allergic rhinitis, chronic idiopathic urticaria, seasonal allergies

Mechanism: Selectively blocks peripheral H1-receptors, inhibiting histamine action. More potent and with fewer CNS effects compared to cetirizine.

Dosage

• Adults & ≥12 yrs: 5 mg once daily (evening preferred)
• Children 6–11 yrs: 2.5–5 mg once daily
• Children 2–5 yrs: 1.25 mg twice daily
• Children 6 mo–2 yrs: 1.25 mg once daily (for urticaria/rhinitis)
• Max dose: 5 mg/day

Major Side Effects

• Drowsiness (rare)
• Fatigue
• Dry mouth
• Headache
• Nasopharyngitis

Contraindications

• Hypersensitivity to levocetirizine, cetirizine, hydroxyzine, or any component
• Severe renal impairment (CrCl <10 mL/min)
• End-stage renal disease or patients on dialysis

Compatible Solvent / Administration

• Oral tablets and oral solution
• Administer with water, with or without food

Special Precautions

• Adjust dose in moderate renal impairment
• Monitor for drowsiness in sensitive individuals
• Safe for children ≥6 months under medical supervision
• Pregnancy Category B – considered relatively safe