Azathioprine

What it is and how it works

Mechanism class: Nucleic Acid Synthesis Inhibitors

Indications

INDICATIONS AND USAGE Azathioprine tablets, USP are indicated as an adjunct for the prevention of rejection in renal homotransplantation. It is also indicated for the management of active rheumatoid arthritis to reduce signs and symptoms. Renal Homotransplantation Azathioprine tablets, USP are indicated as an adjunct for the prevention of rejection in renal homotransplantation. Experience with over 16,000 transplants shows a 5-year patient survival of 35% to 55%, but this is dependent on donor, match for HLA antigens, anti-donor or anti-B-cell alloantigen antibody, and other variables. The effect of azathioprine tablets on these variables has not been tested in controlled trials. Rheumatoid Arthritis Azathioprine tablets, USP are indicated for the treatment of active rheumatoid arthritis (RA) to reduce signs and symptoms. Aspirin, non-steroidal anti-inflammatory drugs and/or low dose glucocorticoids may be continued during treatment with azathioprine tablets.

Dosage and administration (summary)

DOSAGE AND ADMINISTRATION Renal Homotransplantation The dose of azathioprine tablets required to prevent rejection and minimize toxicity will vary with individual patients; this necessitates careful management. The initial dose is usually 3 to 5 mg/kg daily, beginning at the time of transplant. Azathioprine tablets are usually given as a single daily dose on the day of, and in a minority of cases 1 to 3 days before, transplantation. Dose reduction to maintenance levels of 1 to 3 mg/kg daily is usually possible. The dose of azathioprine tablets should not be increased to toxic levels because of threatened rejection.

Contraindications

CONTRAINDICATIONS Azathioprine tablets should not be given to patients who have shown hypersensitivity to the drug. Azathioprine tablets should not be used for treating rheumatoid arthritis in pregnant women. Patients with rheumatoid arthritis previously treated with alkylating agents (cyclophosphamide, chlorambucil, melphalan, or others) may have a prohibitive risk of malignancy if treated with azathioprine tablets.

Warnings and precautions

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.

Pregnancy

Pregnancy Azathioprine tablets can cause fetal harm when administered to a pregnant woman. Azathioprine tablets should not be given during pregnancy without careful weighing of risk versus benefit. Whenever possible, use of azathioprine tablets in pregnant patients should be avoided.

Storage and supply

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…

Source: Azathioprine (Azathioprine) — US FDA prescribing information, 2025-05-19, DailyMed. Summarised and shortened; the full label governs. Iranian registration, indications and labelling may differ.