Meds. There are two brands of honey based cough med that I have seen. One is made by hylands. The other by zarbees. These are ok for a 4 year old. You can also try a vaporizer. You can prop him/her up on a pillow at night. Vicks is also ok to use. If the child has shortness of breath, severe cough, labored breathing, high fever etc. Then you better take him or her to the doctor.