Efficacy and safety of switching to azathioprine for mycophenolate induced diarrhea in renal transplant recipients

Background. Diarrhea is a common adverse effect of mycophenolate treatment in renal transplant recipients. In patients with mycophenolate-induced diarrhea, one option is to switch to mycophenolate to azathioprine. In this study, we aimed to define the safety and efficacy of switching from mycophenolate to azathioprine for mycophenolate-related diarrhea in renal transplant recipients.Methods. A total of 177 patients, 59 of whom were switched to azathioprine because of diarrhea and 118 of whom comprised a matched control group without diarrhea and continued mycophenolate treatment participated in this study. We analyzed the effect of switching to azathioprine from mycophenolate on amelioration of diarrhea and graft survival.Results. We observed that 89.8% of patients who switched to azathioprine because of diarrhea had improved diarrhea complaints. Patients switched to azathioprine because of diarrhea had lower glomerular filtration rates (P < .001) and higher proteinuria (P < .001) compared with the control group before the switch. Patients switched to azathioprine compared with a subgroup of 59 control patients were matched to patients switched to azathioprine in terms of baseline renal function and proteinuria in addition to demographic parameters had higher 10-year graft loss compared with patients who continued mycophenolate (P = .03). Particularly in patients with a glomerular filtration rate <30 mL/min at the time of conversion, the risk of early graft loss was high.Conclusions. Although switching from mycophenolate to azathioprine was an effective approach to improve diarrhea, this approach is associated with increased risk of graft loss.