Mercaptopurine is an immunosuppressive drug. It is a thiopurine. It is used to treat leukemia, pediatric non-Hodgkin's lymphoma, polycythemia vera, psoriatic arthritis, and inflammatory bowel disease. 6-MP ribonucleotide inhibits purine nucleotide synthesis and metabolism by inhibiting an enzyme called Phosphoribosyl pyrophosphate amidotransferase (PRPP Amidotransferase). PRPP Amidotransferase is the rate limiting enzyme of purine synthesis.[8] This alters the synthesis and function of RNA and DNA.[citation needed] Mercaptopurine interferes with nucleotide interconversion and glycoprotein synthesis. Mercaptopurine can lower the body's ability to fight off infection. Those taking it should get permission from a doctor to receive immunizations and vaccinations. It is also recommended that, while on the drug, one should avoid those having recently received oral polio vaccine.
-V678.gif)