Montelukast%2520levocetrizine

# Montelukast / Levocetirizine ## Overview Fixed-dose combination tablet containing a leukotriene receptor antagonist (montelukast 10 mg) and a second-generation antihistamine (levocetirizine 5 mg). Used for allergic rhinitis and asthma. ## Primary Indications - Seasonal and perennial allergic rhinitis with associated mild persistent asthma - Symptom relief of allergic rhinitis not adequately controlled by monotherapy ## Adult Dosing - **One tablet (10 mg/5 mg) orally once daily in the evening** ## Pediatric Dosing - **Not established for this fixed combination.** Doses must be individualized: - Montelukast: ages 6–14 years → 5 mg chewable tablet daily; <6 years → 4 mg granules daily - Levocetirizine: ages 6–11 years → 2.5 mg daily; ≥12 years → 5 mg daily ## Dose Adjustments - **Renal impairment (levocetirizine):** CrCl 30–49 mL/min → 5 mg levocetirizine every other day; CrCl <30 mL/min or dialysis → avoid combination - **Hepatic impairment:** Avoid combination if severe hepatic impairment and renal impairment coexist - No adjustment for montelukast needed in renal or mild-moderate hepatic impairment ## Contraindications - Hypersensitivity to montelukast, levocetirizine, or cetirizine/piperazine derivatives - Severe renal impairment (CrCl <30 mL/min) unless levocetirizine dosed separately with adjustment - End-stage renal disease on dialysis - Pregnancy: limited safety data; avoid unless clearly needed ## Adverse Effects - Common: headache, somnolence, dry mouth, fatigue, pharyngitis - Montelukast: neuropsychiatric events (agitation, aggression, depression, suicidal ideation—rare but serious) - Levocetirizine: somnolence less than first-generation antihistamines but still possible ## Key Drug Interactions - CNS depressants (alcohol, benzodiazepines, opioids) → additive sedation - CYP3A4 inducers (rifampin) may reduce montelukast levels; clinical significance uncertain - Theophylline, warfarin: monitor if co-administered (montelukast interaction potential) ## Monitoring - Neuropsychiatric symptoms (especially mood changes, behavioral effects in children) - Renal function at baseline and periodically; adjust levocetirizine if declining - Asthma control (if used for asthma component) - Sedation level, especially when driving or operating machinery ## Clinical Pearls - Take in the evening to optimize benefit for nocturnal asthma symptoms - Bioavailability of levocetirizine is higher than cetirizine; dose for effect - Onset of action for allergic rhinitis: levocetirizine within 1 hour; full effect of montelukast within days - Do not use for acute asthma attacks; only for maintenance therapy - Neuropsychiatric adverse effects require immediate discontinuation and reporting --- **Disclaimer:** This information is for educational purposes and does not replace clinical judgment. Always verify current prescribing information, local protocols, and official product labeling before dispensing or administering.