Montefast-L is a combination medication used in the management of allergic rhinitis, asthma, and se... Montefast-L is a combination medication used in the management of allergic rhinitis, asthma, and seasonal allergy symptoms. Levocetirizine, a non-sedating antihistamine, relieves symptoms like sneezing, runny nose, and itching, while Montelukast, a leukotriene receptor antagonist, reduces airway inflammation and prevents bronchospasm. See more