My Baby Is 6 Month Old , He Is Having

My baby is 6 month old , he is having cough , Doctor advised to give ambrolite- s cough syrup 2ml for 5 days 3 times a day , He was better after that giving medicines , but now again he's having cough , now am giving 2ml one time a day is that , I can continue the same or is there any side affect . please advise