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Apo-Azathioprine (CA), Azasan, Gen-Azathioprine (CA), Immunoprin (UK), Imuran, Novo-Azathioprine (CA)

Pharmacologic class: Purine antagonist

Therapeutic class: Immunosuppressant

Pregnancy risk category D

FDA Box Warning

• Drug may cause chronic immunosuppression, increasing neoplasia risk. Physicians using it should be familiar with this risk and with possible hematologic toxicities and mutagenic potential in both sexes.


Prevents proliferation and differentiation of activated B and T cells by interfering with synthesis of purine, DNA, and RNA


Injection: 100-mg vial

Tablets: 50 mg, 75 mg, 100 mg

Indications and dosages

To prevent rejection of kidney transplant

Adults and children: Initially, 3 to 5 mg/kg/day P.O. or I.V. as a single dose. Give on day of transplantation or 1 to 3 days before day of transplantation; then 3 to 5 mg/kg/day I.V. after surgery until patient can tolerate P.O. route. Maintenance dosage is 1 to 3 mg/kg/day P.O.

Rheumatoid arthritis

Adults and children: Initially, 1 mg/kg P.O. or I.V. in one or two daily doses. Increase dosage in steps at 6 to 8 weeks and thereafter at 4-week intervals; use dosage increments of 0.5 mg/kg/day, to a maximum dosage of 2.5 mg/kg/day. Once patient stabilizes, decrease in decrements of 0.5 mg/kg/day to lowest effective dosage.

Dosage adjustment

• Renal disease

• Concurrent allopurinol therapy

• Elderly patients

Off-label uses

• Crohn's disease

• Myasthenia gravis

• Chronic ulcerative colitis


• Hypersensitivity to drug

• Pregnancy or breastfeeding


Use cautiously in:

• chickenpox, herpes zoster, impaired hepatic or renal function, decreased bone marrow reserve

• previous therapy with alkylating agents (cyclophosphamide, chlorambucil, melphalan) for rheumatoid arthritis

• elderly patients

• women of childbearing age.


• Give after meals.

• Be aware that I.V. administration is intended for use only when patients can't tolerate oral medications.

Adverse reactions

CNS: malaise

EENT: retinopathy

GI: nausea, vomiting, diarrhea, stomatitis, esophagitis, anorexia, mucositis, pancreatitis

Hematologic: anemia, thrombocytopenia, leukopenia, pancytopenia

Hepatic: jaundice, hepatotoxicity

Musculoskeletal: muscle wasting, joint and muscle pain

Skin: rash, alopecia

Other: chills, fever, serum sickness, neoplasms, serious infection


Drug-drug. Allopurinol: increased therapeutic and adverse effects of azathioprine

Angiotensin-converting enzyme (ACE) inhibitors, co-trimoxazole: severe leukopenia

Anticoagulants, cyclosporine: decreased actions of these drugs

Atracurium, pancuronium, tubocurarine, vecuronium: reversal of these drugs' actions

Drugs affecting bone marrow and bone marrow cells (such as ACE inhibitors, co-trimoxazole): severe leukopenia

Drug-diagnostic tests. Alanine aminotransferase, alkaline phosphatase, amylase, aspartate aminotransferase, bilirubin: increased levels

Albumin, hemoglobin, uric acid: decreased levels

Urine uric acid: decreased level

Drug-herbs. Astragalus, echinacea, melatonin: interference with immunosuppressant action

Patient monitoring

Monitor CBC, platelet level, and liver function test results.

• Assess for signs and symptoms of hepatotoxicity (clay-colored stools, pruritus, jaundice, and dark urine).

• Watch for signs and symptoms of infection.

• Monitor for bleeding tendency and hemorrhage.

Patient teaching

Tell patient that drug lowers resistance to infection. Instruct him to immediately report fever, cough, breathing problems, chills, and other symptoms.

Instruct patient to immediately report unusual bleeding or bruising.

• Tell patient that drug effects may not be obvious for up to 8 weeks in immunosuppression and up to 12 weeks for rheumatoid arthritis relief.

Emphasize importance of avoiding pregnancy during therapy and for 4 months afterward.

• Caution patient to avoid activities that may cause injury. Tell him to use soft toothbrush and electric razor to avoid gum and skin injury.

• Advise patient to minimize GI upset by eating small, frequent servings of food and drinking plenty of fluids.

• Tell patient he'll undergo regular blood testing during therapy.

• As appropriate, review all other significant and life-threatening adverse reactions and interactions, especially those related to the drugs, tests, and herbs mentioned above.

McGraw-Hill Nurse's Drug Handbook, 7th Ed. Copyright © 2013 by The McGraw-Hill Companies, Inc. All rights reserved


A trademark for the drug azathioprine.
The American Heritage® Medical Dictionary Copyright © 2007, 2004 by Houghton Mifflin Company. Published by Houghton Mifflin Company. All rights reserved.


A thiolated purine analogue/immunosuppressant used to prevent rejection of heart, kidney, lung and other allografts, acting primarily on T cells; it is used in rheumatoid arthritis and myasthenia gravis.

Adverse effects
Dose-related marrow suppression—leukopaenia, thrombocytopaenia, macrocytic anaemia); GI tract—nausea, vomiting, diarrhoea, fever, malaise, myalgia, liver enzyme defects, hepatotoxicity, pancreatitis. Azathiprineshould not be given with allopurinol.

Azathioprine is 6-mercaptopurine with a side chain to protect the labile sulfhydryl group, which is split off in the liver; full metabolic activity follows addition of ribose 5-phosphate from phosphoribosyl pyrophosphate that is metabolised to the cytotoxic derivative 6-mercaptopurine.
Segen's Medical Dictionary. © 2012 Farlex, Inc. All rights reserved.


Azathioprine, see there.
McGraw-Hill Concise Dictionary of Modern Medicine. © 2002 by The McGraw-Hill Companies, Inc.


A brand name for AZOTHIAPRINE.
Collins Dictionary of Medicine © Robert M. Youngson 2004, 2005
References in periodicals archive ?
Imuran tablets are now approved for the treatment of steroid-dependent Crohn's disease and steroid-dependent ulcerative colitis in the remission period.
Renal disease patients are sometimes taking Prednisone or Imuran and either one of these drugs can elevate blood sugar levels and/or blood pressure.
Given the choice of taking medications like the steroid prednisone and the immunosuppressant Imuran for years with all the unpleasant side effects, or swallowing some harmless eggs every two weeks with no side effects, which path would you take?
Imuran (azathioprine) has been used when anticholinesterase and steroid therapy fail.
Azathioprine (Imuran) and 6-mercaptopurine (6-MP, marketed as Purinethol), which are metabolically identical, are the most widely used immunosuppressives for children.
As part of MG treatment, pyridostigmine (Mestinon) was the most commonly prescribed drug, followed by prednisone and azathioprine (Imuran) or another immunosuppressive drug.
The three women, all former employees of the company, claim that working with the Imuran drug on packing lines has caused an array of illnesses including cancer and birth defects.
The women all worked producing Imuran for organ transplant patients.
Under her mother's care, Amkia is receiving Imuran, an immunosuppressive drug that often mitigates the symptoms of colitis, a mysterious disease for which there is a wide range of possible remedies, none of them surefire, and no cure.
Immunosuppressives, such as azathioprine (Imuran) and cyclophosphamide (Cytoxan), restrain the overactive immune system by blocking the production of some immune cells and curbing the action of others.
Imuran was the most widely accepted medication for kidney transplant patients in 1983, but Moore decided to try Cyclosporine.
(They have a mixed record on delaying disability.) They are Novantrone, intravenous immunoglobulin or MG, and Imuran (azathioprine).