What Is The Difference Between The Effectiveness Of COR 136 And B 973?

What are the differences in efficacy and side effects between these 2 amphetamines: COR 136 and b 973? I have used the b 973 but just got a prescription for the COR 136. I have heard that the COR pill has more and/or stronger side effects, so I m not sure if I should take these or wait until Monday and return them in exchange for the ones I am used to. Please advise.