...less medical jargon in a 'Quick Glance' format!
Azathioprine Side Effects include:
Some azathioprine side effects can be serious. The following symptoms are uncommon, but if you experience any of them or those listed in the IMPORTANT WARNING section, call your doctor immediately.
lack of energy
loss of appetite
pain in the upper right part of the stomach
yellowing of the skin or eyes
Azathioprine is an immunosuppressant used in organ transplantation, autoimmune disease such as rheumatoid arthritis and pemphigus or inflammatory bowel disease such as Crohn's disease and ulcerative colitis as well as multiple sclerosis. It is a pro-drug, converted in the body to the active metabolites 6-mercaptopurine and 6-thioinosinic acid. It is a purine synthesis inhibitor.
Azathioprine is produced by a number of generic manufacturers and as branded names (Azasan by Salix in the U.S., Imuran by GlaxoSmithKline in Canada and the U.S., Australia and UK, Azamun in Finland and Imurel in Scandinavia).
(Azathioprine Side Effects) Severe leukopenia, thrombocytopenia, macrocytic anemia, and/or pancytopenia may occur in patients being treated with Azathioprine tablets. Severe bone marrow suppression may also occur. Patients with intermediate thiopurine S-methyl transferase (TPMT) activity may be at an increased risk of myelotoxicity if receiving conventional doses of Azathioprine tablets. Patients with low or absent TPMT activity are at an increased risk of developing severe, life-threatening myelotoxicity if receiving conventional doses of Azathioprine tablets. TPMT genotyping or phenotyping can help identify patients who are at an increased risk for developing Azathioprine tablets toxicity2-9. Hematologic toxicities are dose-related and may be more severe in renal transplant patients whose homograft is undergoing rejection. It is suggested that patients on Azathioprine tablets have complete blood counts, including platelet counts, weekly during the first month, twice monthly for the second and third months of treatment, then monthly or more frequently if dosage alterations or other therapy changes are necessary. Delayed hematologic suppression may occur. Prompt reduction in dosage or temporary withdrawal of the drug may be necessary if there is a rapid fall in or persistently low leukocyte count, or other evidence of bone marrow depression. Leukopenia does not correlate with therapeutic effect; therefore the dose should not be increased intentionally to lower the white blood cell count.
Serious infections are a constant hazard for patients receiving chronic immunosuppression, especially for homograft recipients. Fungal, viral, bacterial, and protozoal infections may be fatal and should be treated vigorously. Reduction of Azathioprine dosage and/or use of other drugs should be considered.
Azathioprine tablets are mutagenic in animals and humans, carcinogenic in animals, and may increase the patient’s risk of neoplasia. Renal transplant patients are known to have an increased risk of malignancy, predominantly skin cancer and reticulum cell or lymphomatous tumors. The risk of post-transplant lymphomas may be increased in patients who receive aggressive treatment with immunosuppressive drugs. The degree of immunosuppression is determined, not only by the immunosuppressive regimen, but also by a number of other patient factors. The number of immunosuppressive agents may not necessarily increase the risk of post-transplant lymphomas. However, transplant patients who receive multiple immunosuppressive agents may be at risk for over-immunosuppression; therefore, immunosuppressive drug therapy should be maintained at the lowest effective levels. Information is available on the spontaneous neoplasia risk in rheumatoid arthritis, and on neoplasia following immunosuppressive therapy of other autoimmune diseases. It has not been possible to define the precise risk of neoplasia due to Azathioprine tablets. The data suggest the risk may be elevated in patients with rheumatoid arthritis, though lower than for renal transplant patients. However, acute myelogenous leukemia as well as solid tumors have been reported in patients with rheumatoid arthritis who have received Azathioprine. Data on neoplasia in patients receiving Azathioprine tablets can be found under ADVERSE REACTIONS.