Tioguanine

Overview
Tioguanine (INN), formerly Thioguanine (BAN), is a drug that is used in the treatment of cancer. It belongs to the family of drugs called antimetabolites. It is a guanine analog. Its principal use is in acute leukaemias and chronic myeloid leukaemia.

Pharmacology
As a guanine analogue, it is transformed inside the cell into to 6-thioguanilyic acid (TGMP) which, by pseudofeedback interference with purine biosynthesis, interferes with the synthesis of guanine nucleotides. Some of its activity may also be due to the incorporation of thioguanine nucleotides into both RNA and DNA, but the end result is inducing cell cycle arrest and apoptosis. It is metabolized by via methylation by thiopurine methyltransferase.

Tioguanin Тиогуанин