My son had been on 6mp since October. His initial dose was 50mg but they increase to 75 mg because he was not metabolizing enough of the drug. They just called with his blood work and they are switching back to 50mg with Allopurinol to help him metabolize it better. I have looked up the med and understand why but what other complications does this add to the mix? Why not just prescribe it this way in the first place? Thank you for any advice on this!