Anorexia nervosa in a pediatric renal transplant recipient and its reversal with cyclosporine.

We report a 16-yr-old female who developed AN within a month after renal transplantation and its resolution after switching from tacrolimus to cyclosporine. Her initial maintenance immunosuppressive regimen after renal transplantation consisted of tacrolimus, mycophenolate, and steroid. She had 7 kg weight loss within the first month of transplant with subsequent 10, 12, 17, and 19 kg loss after three, five, seven, and nine months of transplant, respectively. Besides weight loss and disturbances in body image, the patient developed alopecia, bradycardia, and persistent secondary amenorrhea. Upon switching to cyclosporine from tacrolimus nine months after transplant, she started regaining weight with 5 kg gain within two months and 10 kg after four months. She restarted her menstrual cycle, alopecia and bradycardia resolved, and her body image disturbance improved. Here, we describe a very unusual neuropsychiatric side effect of tacrolimus and its resolution with another calcineurin inhibitor, cyclosporine, in an adolescent renal transplant recipient.