A 50 year old male, Ram Lal suffering from renal failure, underwent a kidney transplant. He was prescribed a nucleotide derivative following the organ transplant. The nucleotide derivative of therapeutic importance in this organ transplant is :

Immunosuppressants are used in organ transplantation to prevent the rejection. Most commonly used agents for this purpose are glucocorticoids. Azathioprine is a nucleotide derivative that can be used as an immunosuppressant. 5-Fluorouracil and cytarabine are also nucleotide derivatives but these are used for the treatment of cancers. Allopurinol is used to decrease the production of uric acid. It has no role in renal transplantation.