I agree and even after many years taking an immunosuppressant, suddenly your lab numbers are off. I am 19 1/2 years post kidney transplant and have been on Sirolimus since day one but still, after some labs, my level is suddenly too high or in the low range, prompting the transplant dept. nurses to ask if I'm forgetting to take it on time or did I not wait 24 hrs. after last dose for the lab draw. So, even after these many years, some months they have me take 2 mg., then maybe 1mg., then maybe 2mg., alternating with 1mg.
Same with Cellcept. Taking it since day one, initially 500mg. twice daily, then tapered to 250mg. twice daily. No issues until about a year ago when I developed bad gut issues. Now on Mycophenylate 180mg. twice daily with no issues.
Anyway, used to frustrate me...as if this is my fault when I'm questioned if I'm taking my meds properly. But then I figure, they're just probably following protocol by asking the questions in order to rule out patient error or misunderstanding. And, beats dialysis or worse any day!