My son is 3.5 years old. He had coughing with phlegm. We met two pediatrician on two different occasion. First doc. prescribed only Ascoril-LS for 7 days. During those 7 days coughing was reduced but not completely removed. After that we met another doc. who gave azithromycin 5ml, once day for 5 days. Now things are normal and coughing and phlegm is reduced up-to 90%. But looking at our concern he added lots of other medicines including some immune increasing medicine, multivitamine and Montelukast 10 mg + Levocetirizine dihydrochloride 5 mg. This is first time in his 3.5 years that his cough & phlegm has lasted for 20-25 days without fever. I don t think my son has asthma or allergy. I thing may be due to rainy season. My question is 1. Such long coughing is possible? 2. Is Montelukast safe for children? 3. How to increase immunity in child?