Hi im on Imuran also known as azathioprine and in UK the doseage is dependent on your weight
I weight 62kg and am taking 100mg aday (2 , 50mg tabs) and has to be taken with a heavy meal to prevent sickness, If only a light meal or sugary food is eaten then yes you'd experience sickness an possible vomiting.
If you were to take this medication again then it's best to start on a low dose and build it up over a few weeks, it gives the body time to adjust.
And im not syptom free either .