The combined use of azathioprine tablets with disease modifying anti-rheumatic drugs (DMARDs) has not been studied for either added benefit or unexpected adverse effects. The use of azathioprine tablets with these agents cannot be recommended. Warnings: WARNINGS Malignancy Patients receiving immunosuppressants, including azathioprine, are at increased risk of developing lymphoma and other malignancies, particularly of the skin. Physicians should inform patients of the risk of malignancy with azathioprine. As usual for patients with increased risk for skin cancer, exposure to sunlight and ultraviolet light should be limited by wearing protective clothing and using a sunscreen with a high protection factor. Post-transplant 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, including azathioprine. Therefore, immunosuppressive drug therapy should be maintained at the lowest effective levels. We may limit or otherwise restrict your access to the API in line with our Terms of Service.", "terms": "https://open.fda.gov/terms/", "license": "https://open.fda.gov/license/", "last_updated": "2026-08-07", "results": { "skip": 0, "limit": 1, "total": 1 } }, "results": [ { "spl_product_data_elements": [ "Azathioprine Azathioprine CROSCARMELLOSE SODIUM LACTOSE MONOHYDRATE MAGNESIUM STEARATE POVIDONE, UNSPECIFIED STARCH, CORN AZATHIOPRINE AZATHIOPRINE YELLOW ROUND ZC;59" ], "boxed_warning": [ "WARNING - MALIGNANCY Chronic immunosuppression with azathioprine, a purine antimetabolite increases risk of malignancy in humans. Reports of malignancy include post-transplant lymphoma and hepatosplenic T-cell lymphoma (HSTCL) in patients with inflammatory bowel disease. Physicians using this drug should be very familiar with this risk as well as with the mutagenic potential to both men and women and with possible hematologic toxicities. Physicians should inform patients of the risk of malignancy with azathioprine. See WARNINGS ." ], "description": [ "DESCRIPTION Azathioprine is an immunosuppressive antimetabolite. Each uncoated azathioprine tablet intended for oral administration contains 25 mg or 50 mg or 75 mg or 100 mg of azathioprine. This is not an estimate of the half-life of azathioprine itself, but is the decay rate for all 35 S-containing metabolites of the drug. Because of extensive metabolism, only a fraction of the radioactivity is present as azathioprine. Usual doses produce blood levels of azathioprine, and of mercaptopurine derived from it, which are low ( 50% 28% Toxicity Renal Homograft Rheumatoid Arthritis * Data on the rate and risk of neoplasia among persons with rheumatoid arthritis treated with azathioprine are limited. The incidence of lymphoproliferative disease in patients with RA appears to be significantly higher than that in the general population. In one completed study, the rate of lymphoproliferative disease in RA patients receiving higher than recommended doses of azathioprine (5 mg/kg per day) was 1.8 cases per 1000 patient-years of follow-up, compared with 0.8 cases per 1000 patient-years of follow-up in those not receiving azathioprine. However, the proportion of the increased risk attributable to the azathioprine dosage or to other therapies (i.e., alkylating agents) received by patients treated with azathioprine cannot be determined. Leukopenia (any degree) >50% 28% <2,500 cells/mm 3 16% 5.3% Infections 20% <1% Neoplasia * Lymphoma 0.5% Others 2.8% " ], "overdosage": [ "OVERDOSAGE The oral LD 50 s for single doses of azathioprine tablets in mice and rats are 2500 mg/kg and 400 mg/kg, respectively. Very large doses of this antimetabolite may lead to marrow hypoplasia, bleeding, infection, and death. About 30% of azathioprine is bound to serum proteins, but approximately 45% is removed during an 8-hour hemodialysis. 14 A single case has been reported of a renal transplant patient who ingested a single dose of 7500 mg azathioprine. The dose may be increased, beginning at 6 to 8 weeks and thereafter by steps at 4-week intervals, if there are no serious toxicities and if initial response is unsatisfactory. Dose increments should be 0.5 mg/kg daily, up to a maximum dose of 2.5 mg/kg per day. Therapeutic response occurs after several weeks of treatment, usually 6 to 8; an adequate trial should be a minimum of 12 weeks. Patients not improved after 12 weeks can be considered refractory. Azathioprine tablets may be continued long-term in patients with clinical Patients who are heterozygous for both TPMT and NUDT15 deficiency may require more substantial dosage reductions (see CLINICAL PHARMACOLOGY , WARNINGS: Cytopenias , and PRECAUTIONS: Laboratory Tests ). Use in Renal Dysfunction Relatively oliguric patients, especially those with tubular necrosis in the immediate postcadaveric transplant period, may have delayed clearance of azathioprine tablets or its metabolites, may be particularly sensitive to this drug, and are usually given lower doses. Procedures for proper handling and disposal of this immunosuppressive antimetabolite drug should be considered. Several guidelines on this subject have been published. 15-21 There is no general agreement that all of the procedures recommended in the guidelines are necessary or appropriate." ], "how_supplied": [ "HOW SUPPLIED Azathioprine Tablets USP, 50 mg are yellow, round, flat, beveled edge tablets with bisect on one side; one side of the bisect is debossed with logo of \"ZC\" and other side is debossed with \"59\" and other side is plain and are supplied as follows: Unit dose packages of 100 (10 x 10) NDC 68084-229-01 STORAGE Store at 20°C to 25°C (68°F to 77°F) [See USP Controlled Room Temperature] in a dry place and protect from light. FOR YOUR PROTECTION: Do not use if blister is torn or broken.

[Occurrence of malignant non-Hodgkin lymphoma after long-term azathioprine therapy of chronic polyarthritis]. The case is presented of a female patient with rheumatoid arthritis, in whom a malignant non-Hodgkin lymphoma developed following long-term treatment with azathioprine. The possibility of an increased incidence of malignant lymphomas in immunological disorders, including rheumatoid arthritis, is discussed, as is the question of the extent to which azathioprine therapy might be involved in this. Some pathogenetic mechanisms of the development of malignant lymphomas are also considered. Published in Zeitschrift fur Rheumatologie