I had an allergic reaction to Purinethol. I developed pancreatitis; pericarditis and I had problems breathing. I asked my doctor to check but he thought it was not a reaction but later he agreed. If you are going to take this drug, check it first on how it might affect you and pay attention to how you are reacting to it. It might be very dangerous. I heard that It works on other people, so it might work on you too but make sure you not have a toxic reaction towards the drug, it could be lethal.