Hi, Ezee cough syrup contains phenylephrine, dextromethorphan and chlorpheniramine maleate. Montair LC contains Monteleukast and Levocetirizine. Phenylephrine is a sympathomimetic drug which constricts the blood vessels and reduces the nasal congestion. Dextromethorphan is an antitussive agent acts in the central nervous system suppressing the cough. Chlorpheniramine maleate is an antihistaminic helps in allergy and inflammatory response. Monteleukast is leukotriene receptor inhibitor reduces the allergic reaction and inflammation of the smooth muscles. Levocetirizine is an antihistaminic with similar function. Since both have additive effect in the respiratory system, any one is enough for treating the common cold. If the symptoms persist or there is cough, fever or breathing difficulty, visit a paediatrician. On using both syrup and tablet may suppress the normal breathing cycle. Take care. Hope I have answered your question. Let me know if I can assist you further. Regards, Dr. Pradeepraj, General & Family Physician