My Son Is 8 Year Old, He Is Very Slow

My son is 8 year old, he is very slow writter & reader, so obviously adverslly effecting his study, he almost doesn't read & write his question paper. he always wants to play & run away when we ask for study. we have consulted a doctor he syggested attentrol 10mg for 10 days & then 18mg for next 10 days. pls suggest is it ok to have this medicine at this age and pls let me know how it works in our body and after how long it will start showing results.