...vicodin? there any tests i can take? lets say i get prescribed vicodin in the future. how do i know if i am allergic to it if vicodin is an anolouge of codein?

a doctor told me that ALOT of people are allergic to codeine. i think he said he doesnt like to prescribe it because so many people have problems with it.

however i know that vicodin is the most prescribed opiate of them all. so there has to be a MAJOR difference between the two