Pain Syndrome and Ventricular Arrhythmia Induced by Sirolimus and Resolved by Dosage Adjustment in a Child After Heart Transplant: A Case Report.

For patients with late congenital heart diseases and advanced heart failure, heart transplant is the one of the most effective known treatment methods. With the development of immunosuppressive medicines, it is possible to prevent and treat rejection, and survival after organ transplant has increased rapidly. Calcineurin inhibitors (tacrolimus and cyclosporine), mycophenolate mofetil, and corticosteroids are used together in many centers as immunosuppressive medications. Although the use of calcineurin inhibitors is essential, therapy is switched to sirolimus in some specific cases and when significant adverse effects occur. The most seen sirolimus-based adverse effects are diarrhea, constipation, vomiting, nausea, abdominal pain, leg pain, acne, headache, and sleep problems. Here, we present a patient who had abdominal pain, nausea, vomiting, and ventricular extrasystole attacks due to sirolimus toxicity, which improved with dose adjustment during follow-up after heart transplant. Pain associated with the use of calcineurin inhibitors improving with sirolimus has been previously reported before; however, because we did not encounter pain syndrome associated with use of sirolimus, we chose to report our experience with this patient.