How Long Should My Toddler Take Sinarest Syrup For A Bad Cough?

Hello Doctor, My daughter is 3 yrs old and 14 kgs. she is having very bad cough n little cold from last 2 days , we started giving Sinarest syrup, 4 ml in morning n 4 ml in night. Please advise how many days we need to use the syrup and the quantity n still she is coughing. Please help