My Son Had A Primary Complex When He Was 2

my son had a primary complex when he was 2 yrs old but i discontinue his medication because he was just vomitting the medicines. now that he is 15 years old his doctor said that he has still the bacteria in his lungs after an x ray and she advised us to start taking the 6month medication again. my concern is the the myrin p forte appropriate for his age? this is the med she prescribed...my son weighs 38kilos and 5'2 in height