Efficacy and safety of switching from mycophenolate to azathioprine in renal transplant patients due to diarrhea side effect

Mycophenolate is a commonly used immunosuppressive drug after renal transplantation. Diarrhea is one of the most common side effects of mycophenolate treatment in clinical practice. In patients with drug-induced diarrhea under mycophenolate treatment, one of the options is to switch from mycophenolate to azathioprine. In this study, we aimed to investigate the effect of switch from mycophenolate to azathioprine on amelioration of diarrhea complaints and the risks on rejection and graft and patient survival. A total of 177 patients, 59 of whom were switched to azathioprine and 118 of which were control group, participated in this study. Basal glomerular filtration rate was lower in the patients who were switched to azathioprine than the control group (p <0.0001); basal creatinine (p = 0.001) and basal proteinuria (p = 0.004) values were higher than the control group. It was observed that 89.8% of the patients who switched to azathioprine due to diarrhea had improved diarrhea complaints. It was shown that 83.3% of the patients whose diarrhea complaints did not improve despite switching to azathioprine had a diagnosis of amyloidosis. Patients that received azathioprine had more graft loss than patients continued mycophenolate (p = 0.004). Particularly in patients with a glomerular filtration rate of less than 30 ml/min at the time of conversion, the risk of graft loss increased after switching from mycophenolate to azathioprine due to diarrhea. In conclusion for selected patients, discontinuation of mycophenolate treatment due to diarrhea and initiation of azathioprine treatment was found to be an effective approach to improve diarrhea complaints.