Fig. 5.

Metabolic pathway of thiopurines.

6-MMP, 6-methyl-mercaptopurine; 6-meTIMP, 6-methyl-thioinosine monophosphate; TPMT, thiopurine S-methyl transferase; AZA, azathioprine; 6-MP, 6-mercaptopurine; 6-TIMP, 6-thioinosine monophosphate; 6-TGN, 6-thioguanine nucleotides; HPRT, hypoxanthine phosphoribosyl transferase; XO, xanthine oxidase; 6-TU, 6-thiouric acid; 6-TGMP, 6-thioguanosine monophosphate; 6-TGDP, 6-thioguanine diphosphate; 6-TGTP, 6-thioguanosine triphosphate. Modified from Nakase H. To master the optimal therapy for ulcerative colitis. Tokyo: Igakutokangosha Co., Ltd., 2018, with permission.²