Doctors typically prescribe this combination for: Seasonal Allergic Rhinitis: Sneezing, itchy nose, and watery eyes caused by pollen or dust. Perennial Allergic Rhinitis: Year-round allergies (like pet dander or mold). Asthma Management: Helping to prevent exercise-induced asthma or managing mild persistent asthma alongside allergies.

These two drugs work through different pathways to stop your body from overreacting to allergens: Levocetirizine Hydrochloride: This is a second-generation antihistamine. It blocks histamine, the chemical your body produces during an allergic reaction that causes itching, sneezing, and a runny nose. Unlike older antihistamines, it is designed to be less sedating. Montelukast Sodium: This is a leukotriene receptor antagonist. It blocks leukotrienes, which are chemicals that cause swelling in your lungs and tightening of the muscles around your airways. It is particularly good at handling the "congestion" and "chest tightness" side of allergies.

Common Side Effects Fatigue, dry mouth, headache, or mild sleepiness.