Montelukast%252525252525252525252525252525252525252525252520levocetrizine

# Montelukast/Levocetirizine ## Overview This is a fixed-dose combination of montelukast, a leukotriene receptor antagonist, and levocetirizine, a second-generation antihistamine. ## Primary Indications * Allergic rhinitis * Chronic idiopathic urticaria ## Adult Dosing * **Montelukast 10 mg / Levocetirizine 5 mg:** One tablet by mouth once daily. ## Pediatric Dosing Dosing varies significantly by age and weight. Fixed-dose combination products are not available for all pediatric age groups or strengths. Refer to individual drug monographs for specific pediatric dosing. * **Montelukast:** * **6 months to 5 years:** 4 mg orally once daily. * **6 years to 14 years:** 5 mg orally once daily. * **15 years and older:** 10 mg orally once daily. * **Levocetirizine:** * **6 months to 11 months:** 1.25 mg orally once daily. * **1 year to 5 years:** 1.875 mg orally once daily. * **6 years to 11 years:** 2.5 mg orally once daily. * **12 years and older:** 5 mg orally once daily. ## Dose Adjustments * **Renal Impairment (Levocetirizine component):** * CrCl 31-50 mL/min: Reduce dose by 50% (e.g., 2.5 mg levocetirizine every other day). * CrCl 5-30 mL/min: Reduce dose by 75% (e.g., 2.5 mg levocetirizine every other day or 1.25 mg daily). * End-stage renal disease or CrCl < 5 mL/min: Generally not recommended, or dose adjustment via individual drug may be needed (consult prescribing information). * **Hepatic Impairment:** No specific dose adjustment recommended for montelukast. Limited data for levocetirizine, but generally no dose adjustment needed. ## Contraindications * Hypersensitivity to montelukast, levocetirizine, other piperazines, or any component of the formulation. * Severe renal impairment (for levocetirizine component). ## Adverse Effects * **Montelukast:** Headache, abdominal pain, dizziness, rash. Neuropsychiatric events (e.g., depression, suicidal ideation) have been reported; use with caution and monitor closely. * **Levocetirizine:** Somnolence (drowsiness), fatigue, dry mouth, pharyngitis. ## Key Drug Interactions * **CNS Depressants (e.g., sedatives, hypnotics, opioids):** Increased additive CNS depression with levocetirizine. * **Theophylline:** Montelukast may decrease theophylline clearance, potentially increasing theophylline levels. Monitor theophylline levels if concurrent use. ## Monitoring * Monitor for efficacy in symptom control of allergic rhinitis and urticaria. * Monitor for adverse effects, especially neuropsychiatric symptoms with montelukast and somnolence with levocetirizine. ## Clinical Pearls * Montelukast is an add-on therapy and should not replace inhaled or oral corticosteroids for asthma management. * The levocetirizine component can cause significant drowsiness; caution patients about operating machinery or performing hazardous tasks. * Ensure patients are not taking other products containing montelukast or levocetirizine to avoid overdose. *** **Disclaimer:** This information is intended for healthcare professionals. Always consult the most current prescribing information and relevant guidelines for complete details and to verify dosages and safety information before initiating therapy.