Colonic ulcers secondary to sirolimus toxicity in a renal transplant recipient

Rapamycin is an immunosuppressive agent which acts as an inhibitor of the mTOR complex. There have been several side effects described. The majority of these drug complications are correlated with sirolimus (SRL) plasma levels. The appearance of oral aphthous ulcers during treatment with SRL has been extensively described. The ulcers are dose dependant. Oesophageal, gastroduodenal and small bowel ulcers have been described in addition to oral ulcers. Colonic ulcers have not been described to date. We report a case of a patient who underwent renal transplantation and developed colonic ulcers secondary to high rapamycin levels.