Montelukast + Levocetirizine

Montelukast, a selective leukotriene receptor antagonist, blocks CysLT1 receptors, thereby inhibiting the effects of leukotrienes in the airway, reducing bronchoconstriction, inflammation, and mucus secretion. Levocetirizine, a potent and selective H1-receptor antagonist, competes with histamine for H1-receptors, preventing the activation of these receptors and thus reducing symptoms like sneezing, rhinorrhea, pruritus, and urticaria. The combination provides synergistic action by addressing both the inflammatory (leukotriene-mediated) and immediate hypersensitivity (histamine-mediated) components of allergic diseases. Combination rationale: This FDC offers comprehensive treatment for allergic and asthmatic conditions by simultaneously targeting two distinct inflammatory pathways: the leukotriene pathway (Montelukast) and the histamine pathway (Levocetirizine). This dual mechanism provides superior symptom control compared to monotherapy, especially in patients with co-existing allergic rhinitis and asthma, or those whose symptoms are not adequately controlled by a single agent. It aims to reduce both acute allergic reactions and chronic inflammatory processes.

Adult

Montelukast 10mg + Levocetirizine 5mg once daily, orally, preferably in the evening.

Pediatric

Children 6-12 years: Montelukast 5mg + Levocetirizine 2.5mg once daily, orally. Children 2-5 years: Montelukast 4mg + Levocetirizine 2.5mg once daily (often available in chewable tablet or oral solution formulations).

Renal adjustment

For Levocetirizine component: CrCl 30-49 mL/min: 5mg every 2 days; CrCl 10-29 mL/min: 5mg twice weekly. Montelukast does not require dose adjustment in renal impairment.

Hepatic adjustment

Montelukast does not require dose adjustment in mild to moderate hepatic impairment. Levocetirizine is minimally metabolized by the liver; no specific adjustment is generally needed, but use with caution in severe hepatic dysfunction.

Geriatric

Start with the lower end of the dosing range and monitor renal function, as elderly patients may have reduced renal clearance of Levocetirizine.

Max dose

Montelukast 10mg/day, Levocetirizine 5mg/day. The FDC typically provides these maximum doses for adults.

• Hypersensitivity to Montelukast, Levocetirizine, or any piperazine derivative
• Severe renal impairment (CrCl < 10 mL/min for Levocetirizine)
• Severe hepatic impairment (use with caution)
• Patients with rare hereditary problems of galactose intolerance, the Lapp lactase deficiency or glucose-galactose malabsorption