Montelukast%2525252525252525252525252525252525252525252525252525252525252525252520levocetrizine

# Montelukast/Levocetirizine ## Overview Montelukast is a leukotriene receptor antagonist. Levocetirizine is a second-generation antihistamine. This combination is used for the symptomatic treatment of allergic rhinitis. Dosage forms include tablets and oral granules/chewable tablets. ## Primary Indications Symptomatic treatment of allergic rhinitis (seasonal and perennial). ## Adult Dosing **Montelukast 10 mg / Levocetirizine 5 mg:** One tablet daily, taken in the evening. ## Pediatric Dosing **Montelukast 4 mg / Levocetirizine 1.25 mg (Chewable Tablet/Oral Granules):** Children 6 months to 5 years: 1 packet/tablet daily. **Montelukast 5 mg / Levocetirizine 2.5 mg (Chewable Tablet/Tablet):** Children 6 to 11 years: 1 tablet daily. *Note: Specific pediatric dosing may vary based on licensed indication and local protocols. Ensure age-appropriateness of formulation.* ## Dose Adjustments No dose adjustment is typically required for renal or hepatic impairment, but caution is advised. Levocetirizine is renally eliminated. ## Contraindications Hypersensitivity to montelukast, levocetirizine, or any component of the formulation. Patients with phenylketonuria should not use chewable formulations containing aspartame. ## Adverse Effects Common: Somnolence, fatigue, dry mouth, pharyngitis, cough, diarrhea, headache, abdominal pain, nausea. Psychiatric effects with montelukast (e.g., agitation, depression, suicidal thoughts) have been reported and require careful monitoring. ## Key Drug Interactions * **CNS Depressants:** Additive sedative effects with alcohol, benzodiazepines, opioids, and other sedating antihistamines. * **CYP Inhibitors/Inducers:** Montelukast is metabolized by CYP1A2, 2C8, and 2C9. Fluoxetine and gemfibrozil may increase montelukast levels. Phenobarbital may decrease montelukast levels. Levocetirizine is primarily eliminated unchanged by the kidneys, thus less prone to CYP interactions. ## Monitoring * Monitor for neurological and behavioral changes, especially in pediatric patients. * Assess efficacy in symptom control of allergic rhinitis. ## Clinical Pearls * Montelukast/levocetirizine can be taken with or without food. * Levocetirizine can cause somnolence; advise patients to use caution when driving or operating machinery. * Discontinue montelukast if psychiatric symptoms occur and assess the benefit-risk profile. * For children under 6 months, use of montelukast alone or levocetirizine alone may be more appropriate, guided by clinical assessment. *** *Disclaimer: This information is intended for healthcare professionals. Always consult the most current prescribing information and local guidelines for definitive dosing, administration, and safety guidance.*