KROKAST is used for a congestion-free breathing with Levocetirizine 2. 5mg+Montelukast Sodium 4 mg. Levocetirizine is a rapid onset & long duration of activity. It has the low potential for interaction with drugs metabolized by the hepatic cytochrome P450 system. It is more effective than other H1 receptor antagonists at inhibiting histamine-induced wheal and flare responses. Montelukast reduces the bronchoconstriction caused by the leukotrienes. it controls both early and late phase of all allergies rhinitis.