It is also an important therapy and steroid-sparing agent for inflammatory bowel disease (such as Crohns disease and ulcerative colitis) and for multiple sclerosis.In the United States, it is approved by the Food and Drug Administration  for use in kidney transplantation from human donors, and for rheumatoid arthritis. Transplantation
Azathioprine is used to prevent rejections of kidney or liver allografts, usually in conjunction with other therapies including corticosteroids, other immunosuppressants, and local radiation therapy. The administration protocol starts either at the time of transplantation or within the following two days. Rheumatoid arthritis
Being a disease-modifying antirheumatic drug (DMARD), azathioprine has been used for the management of the signs and symptoms of adult rheumatoid arthritis. Nonsteroidal anti-inflammatory drugs  and corticosteroids may be combined or continued (if they were already in use) with azathioprine, but the combination with other DMARDs is not recommended. Inflammatory bowel disease
Azathioprine has been used in the management of moderate to severe chronically active Crohns disease, to maintain clinical remission (absence of disease activity) in corticosteroid-dependent patients, and to provide benefit in people with fistulizing Crohns disease. The onset of action is slow, and it may require several months to achieve clinical response.Azathioprine treatment is associated with an increased risk of lymphoma, but if this is due to the drug or a predisposition related to Crohns disease is unclear. Lower doses of azathioprine are used as a therapy in children with refractory or corticosteroid-dependent Crohns disease, without causing many side effects. It may also be used to prevent flares in those with ulcerative colitis.
Floxuridine (also 5-fluorodeoxyuridine) is an oncology drug that belongs to the class known as antimetabolites. Specifically, floxuridine is a pyrimidine analog, classified as a deoxyuridine. The drug is usually administered via an artery, and most often used in the treatment of colorectal cancer. The quality of life and survival rates of individuals that receive continuous hepatic artery infusion of floxuridine for colorectal cancer metastases is significantly higher than control groups. Floxuridine can also be prescribed for the treatment of kidney and stomach cancers. In vitro uses of floxuridine include 5-minute treatments of fluorouracil, floxuridine, and mitomycin to increase cell proliferation in Tenons capsule fibroblasts. Biosynthesis
Immobilized Aeromonas salmonicida ATCC 27013, when exposed to thymidine and 5-fluorouracil in phosphate buffer at room temperature for one hour, can synthesize floxuridine and thymine. Pharmacology
Floxuridine primarily works by stopping the growth of newly born cells. The drug essentially stops DNA from forming in new and rapidly developing cells, which is a sign of a cancerous cell. Therefore, the floxuridine kills the cancerous cells. For colorectal cancer and hepatic metastases, an average adult should be given an intra-arterial dosage of 0.1–0.6 mg/kg/day as a continuous infusion, continued until intolerable toxicity is reached (white blood cell count < 3,500/mm3 or platelet count < 100,000/mm3). Lethal dosages for other species are below. LD50 is the lethal dose at which half of organisms exposed to the drug die. Pharmacodynamics
Floxuridine is a pyrimidine analog that acts as an inhibitor of the S-phase of cell division. This selectively kills rapidly dividing cells.