I took this with Prednisolone for a while before ttc with DD when taken off it as not suitable during pg. Went back onto Azathiaprine earlier this year and, after some trial and error, have realised that it makes me feel VERY unwell - what I call "clinically" tired! not sleepy or sleep deprived, but unable to function. So I have taken myself off it and feel much better. I discussed this with the Drs at my last appt who had double the dose and they agreed to halve it again but they seemed to be unaware of such a side effect. I have an appt coming up soon but wanted to ask if anyone else has experienced this?