Bilastine is an antihistamine that blocks histamine (a substance in the body that causes allergies). It helps reduce sneezing, runny nose, itching, watery eyes, and skin allergies.

Montelukast is a leukotriene receptor antagonist that prevents substances (leukotrienes) in the body from causing swelling, wheezing, and breathing difficulty.

Together, they are useful for treating allergies and asthma-related symptoms in children.