Can Mucolite Be Given To A Child For Cold And Cough With Phlegm?

Hello doctor I have four years son from past three four days he suffer from cold and cough.I used rhimathiol syrup but no improved Docter again prescribed amydramine syrup I used only two days. No improved so now I want start mucolite is it OK.last time it gives good result.his chest has flum is there.Pls give u r openion .thank u