Azathioprine
"I have  Wegener's granulomatosis (aka granulomatosis with polyangiitis) .Was on Imuram for two years, have to switch to Neoral now. Apparently it's not working as it should be. Dreading the switch however, because Imuran gave me few to no side effects. Have experienced hair loss after about a year, but could also have a different cause (I take lots of other medication and many non-drug related causes have to be considered as well, eg hormones, stress,...). Also very cheap drug for me, but we have universal health care in Belgium so don't know of this is also the case elsewhere."