Displaying 10 results of Mercaptopurine Stable Isotopes Mercaptopurine is a chemotherapy drug used to treat acute lymphoblastic leukemia and inflammatory bowel disease. Stable isotopes of mercaptopurine are isotopes that do not undergo radioactive decay. These isotopes are used in research studies to understand the metabolism and pharmacokinetics of the drug, as well as to develop new drug therapies. They are also used in medical imaging and diagnostics.