Azathioprine, Uses, Dosage, Side Effects, Interactions, Pregnancy

Patient Tools

Read, save, and share this guide

Use these quick tools to make this medical article easier to read, print, save, or share with a family member.

Patient Mode

Understand this article easily

Switch between simple English and easy Bangla patient notes. This is for education and does not replace a doctor consultation.

Azathioprine is a purine analog with cytotoxic and immunosuppressive activity. Azathioprine is a prodrug that is converted by hepatic xanthine oxidase to its active metabolite 6-mercaptopurine (6-MP). 6-MP is further metabolized by hypoxanthine-guanine phosphoribosyltransferase (HGPRT) into 6-thioguanosine-5'-phosphate (6-thio-GMP) and 6-thioinosine monophosphate (6-thio-IMP), both inhibit nucleotide conversions and de novo purine synthesis. This leads to inhibition of DNA, RNA, and protein synthesis. As...

For severe symptoms, danger signs, pregnancy, child illness, or sudden worsening, seek urgent medical care.

বাংলা রোগী নোট এখনো যোগ করা হয়নি। পোস্ট এডিটরে “RX Bangla Patient Mode” বক্স থেকে সহজ বাংলা সারাংশ যোগ করুন।

এই তথ্য শিক্ষা ও সচেতনতার জন্য। এটি ডাক্তারি পরীক্ষা, রোগ নির্ণয় বা প্রেসক্রিপশনের বিকল্প নয়।

Article Summary

Azathioprine is a purine analog with cytotoxic and immunosuppressive activity. Azathioprine is a prodrug that is converted by hepatic xanthine oxidase to its active metabolite 6-mercaptopurine (6-MP). 6-MP is further metabolized by hypoxanthine-guanine phosphoribosyltransferase (HGPRT) into 6-thioguanosine-5'-phosphate (6-thio-GMP) and 6-thioinosine monophosphate (6-thio-IMP), both inhibit nucleotide conversions and de novo purine synthesis. This leads to inhibition of DNA, RNA, and protein synthesis. As a result, cell proliferation may be inhibited, particularly in lymphocytes and leukocytes. Azathioprine(AZA) is an immunosuppressive medication used in rheumatoid arthritis, Crohn's disease, ulcerative...

Key Takeaways

  • This article explains Mechanism of Action of Azathioprine in simple medical language.
  • This article explains Indications of Azathioprine in simple medical language.
  • This article explains Contra Indication of Azathioprine in simple medical language.
  • This article explains Dosage of Azathioprine in simple medical language.
Educational health guideWritten for patient understanding and clinical awareness.
Reviewed content workflowUse writer and reviewer profiles for stronger trust.
Emergency safety firstUrgent warning signs are highlighted below.

Seek urgent medical care if you notice

These warning signs are general safety guidance. Local emergency numbers and clinical judgment should always come first.

  • Severe symptoms, breathing difficulty, fainting, confusion, or rapidly worsening illness.
  • New weakness, severe pain, high fever, or symptoms after a serious injury.
  • Any symptom that feels urgent, unusual, or unsafe for the patient.
1

Emergency now

Use emergency care for severe, sudden, rapidly worsening, or life-threatening symptoms.

2

See a doctor

Book a professional medical evaluation if symptoms persist, worsen, recur often, affect daily activities, or occur in a high-risk patient.

3

Learn safely

Use this article to understand possible causes, tests, treatment options, prevention, and questions to ask your clinician.

Azathioprine is a purine analog with cytotoxic and immunosuppressive activity. Azathioprine is a prodrug that is converted by hepatic xanthine oxidase to its active metabolite 6-mercaptopurine (6-MP). 6-MP is further metabolized by hypoxanthine-guanine phosphoribosyltransferase (HGPRT) into 6-thioguanosine-5′-phosphate (6-thio-GMP) and 6-thioinosine monophosphate (6-thio-IMP), both inhibit nucleotide conversions and de novo purine synthesis. This leads to inhibition of DNA, RNA, and protein synthesis. As a result, cell proliferation may be inhibited, particularly in lymphocytes and leukocytes.

Azathioprine(AZA) is an immunosuppressive medication used in pain, swelling, stiffness, or reduced movement. সহজ বাংলা: জয়েন্টের প্রদাহ।" data-rx-term="arthritis" data-rx-definition="Arthritis means joint inflammation causing pain, swelling, stiffness, or reduced movement. সহজ বাংলা: জয়েন্টের প্রদাহ।">arthritis: Rheumatoid arthritis is an autoimmune joint disease causing infection, or irritation, often causing pain, swelling, heat, or redness. সহজ বাংলা: শরীরের প্রদাহ; ব্যথা, ফোলা বা লালভাব হতে পারে।" data-rx-term="inflammation" data-rx-definition="Inflammation is the body’s response to injury, infection, or irritation, often causing pain, swelling, heat, or redness. সহজ বাংলা: শরীরের প্রদাহ; ব্যথা, ফোলা বা লালভাব হতে পারে।">inflammation, pain, and swelling. সহজ বাংলা: রোগপ্রতিরোধ ব্যবস্থার ভুল আক্রমণে জয়েন্টের প্রদাহ।" data-rx-term="rheumatoid arthritis" data-rx-definition="Rheumatoid arthritis is an autoimmune joint disease causing inflammation, pain, and swelling. সহজ বাংলা: রোগপ্রতিরোধ ব্যবস্থার ভুল আক্রমণে জয়েন্টের প্রদাহ।">rheumatoid arthritis, Crohn’s disease, ulcerative colitis, and in kidney transplants to prevent rejection. It is taken by mouth or injected into a vein. An immunosuppressive antimetabolite pro-drug. It is an imidazolyl derivative of 6-mercaptopurine and many of its biological effects are similar to those of the parent compound. Azathioprine is converted into 6-mercaptopurine in the body where it blocks purine metabolism and DNA synthesis.

Mechanism of Action of Azathioprine

Azathioprine antagonizes purine metabolism and may inhibit synthesis of DNA, RNA, and proteins. It may also interfere with cellular metabolism and inhibit mitosis. Its mechanism of action is likely due to the incorporation of thiopurine analogs into the DNA structure, causing chain termination and cytotoxicity. Azathioprine is a chemotherapy drug, now rarely used for chemotherapy but more for immunosuppression in organ transplantation and autoimmune diseases such as pain, swelling, stiffness, or reduced movement. সহজ বাংলা: জয়েন্টের প্রদাহ।" data-rx-term="arthritis" data-rx-definition="Arthritis means joint inflammation causing pain, swelling, stiffness, or reduced movement. সহজ বাংলা: জয়েন্টের প্রদাহ।">arthritis: Rheumatoid arthritis is an autoimmune joint disease causing infection, or irritation, often causing pain, swelling, heat, or redness. সহজ বাংলা: শরীরের প্রদাহ; ব্যথা, ফোলা বা লালভাব হতে পারে।" data-rx-term="inflammation" data-rx-definition="Inflammation is the body’s response to injury, infection, or irritation, often causing pain, swelling, heat, or redness. সহজ বাংলা: শরীরের প্রদাহ; ব্যথা, ফোলা বা লালভাব হতে পারে।">inflammation, pain, and swelling. সহজ বাংলা: রোগপ্রতিরোধ ব্যবস্থার ভুল আক্রমণে জয়েন্টের প্রদাহ।" data-rx-term="rheumatoid arthritis" data-rx-definition="Rheumatoid arthritis is an autoimmune joint disease causing inflammation, pain, and swelling. সহজ বাংলা: রোগপ্রতিরোধ ব্যবস্থার ভুল আক্রমণে জয়েন্টের প্রদাহ।">rheumatoid arthritis or inflammatory bowel disease or Crohn’s disease. It is a pro-drug, converted in the body to the active metabolite 6-mercaptopurine. Azathioprine acts to inhibit purine synthesis necessary for the proliferation of cells, especially leukocytes and lymphocytes. It is a safe and effective drug used alone in certain autoimmune diseases, or in combination with other immunosuppressants in organ transplantation. Its most severe side effect is bone marrow suppression, and it should not be given in conjunction with purine analogs such as allopurinol. The enzyme thiopurine S-methyltransferase (TPMT) deactivates 6-mercaptopurine. Genetic polymorphisms of TPMT can lead to excessive drug toxicity, thus the assay of serum TPMT may be useful to prevent this complication.

Azathioprine (AZA), one of the antimetabolite drugs, is a purine analog that is more potent than the prototype 6-mercaptopurine, as an inhibitor of cell replication. Immunosuppression likely occurs because of the ability of the drug to inhibit purine biosynthesis. Although T-cell functions are the primary targets for this drug, inhibition of /(natural killer cells)/ NK function and macrophage activities have also been reported.
Azathioprine inhibits DNA synthesis and, as a purine antimetabolite, exerts its effect on activated lymphocytes, which requires purines during their proliferative phase. It inhibits both cellular and humoral responses but does not interfere with phagocytosis or interferon production. It is a nonspecific cytotoxic agent. Its immunosuppressive effect is believed to be due to mercaptopurine, to which it is metabolized.
The exact mechanism of immunosuppressive action is unknown since the exact mechanism of the immune response itself is complex and not completely understood. The immunosuppressive effects of azathioprine involve a greater suppression of delayed hypersensitivity and cellular cytotoxicity tests than of antibody responses. Azathioprine antagonizes purine metabolism and may inhibit synthesis of DNA, RNA, and proteins; it may also interfere with cellular metabolism and inhibit mitosis.
or
The thiopurines, azathioprine and 6 MP are potent inhibitors of both experimental and clinical immune responses. The primary pharmacological activities are mediated by competitive inhibition of enzymes concerned with de novo purine base synthesis; Immunosuppressive activities appear to result from cytotoxic activities directed against antigen-responsive lymphocytes; this inhibition is maximal when the treatment course coincides with the proliferative expansion phase of the response. By contrast, thiopurines are comparatively ineffective if used during an effector phase of an immune response. Furthermore, administration prior to antigenic challenge does not lead to immune inhibition; in fact, it may lead to augmentation of selected immune responses. Treatment with thiopurines does not result in acute lymphopenia; prolonged courses will cause a moderate decrease in circulating lymphocytes. The drug does not selectively deplete peripheral T or B cells but can acutely reduce K (killer) cells, which are effectors in ADCC responses. In addition, short-lived thymocytes and marrow lymphocytes are rapidly depleted by these anti-metabolites. Many in vitro functions of lymphocytes, from treated animals remain normal. Recent studies indicate that, in vitro, azathioprine is specifically able to bind murine T lymphocytes; this can be shown by their ability to inhibit their capacity to rosette with sheep erythrocytes. Azathioprine is also a potent inhibitor of mixed lymphocyte culture responses and can readily suppress the in vitro generation of cytotoxic T cells. These observations suggest that drugs exert preferential toxicities for murine T cells. B lymphocytes for mice appear to vary in their susceptibility for thiopurines. By contrast, the activity of human B cells can be readily suppressed with this drug whereas T helper function is comparatively resistant. In addition to immunosuppressive properties, thiopurines are capable of exerting infection, or irritation, often causing pain, swelling, heat, or redness. সহজ বাংলা: শরীরের প্রদাহ; ব্যথা, ফোলা বা লালভাব হতে পারে।" data-rx-term="inflammation" data-rx-definition="Inflammation is the body’s response to injury, infection, or irritation, often causing pain, swelling, heat, or redness. সহজ বাংলা: শরীরের প্রদাহ; ব্যথা, ফোলা বা লালভাব হতে পারে।">inflammation, pain, or swelling. সহজ বাংলা: প্রদাহ/ফোলা/ব্যথা কমায়।" data-rx-term="anti-inflammatory" data-rx-definition="Anti-inflammatory means reducing inflammation, pain, or swelling. সহজ বাংলা: প্রদাহ/ফোলা/ব্যথা কমায়।">anti-inflammatory activities, primarily by inhibiting the replication of hematopoietic precursors.

Indications of Azathioprine

  • Azathioprine is an immunosuppressive agent used in combination with cyclophosphamide and hydroxychloroquine in the treatment of rheumatoid arthritis. 
  • Rheumatoid Arthritis
  • Psoriatic Arthritis
  • Renal Transplant
  • Autoimmune Hepatitis
  • Crohn’s Disease
  • Atopic Dermatitis
  • Behcet’s Disease
  • Biliary Cirrhosis
  • Bullous Pemphigoid
  • Chronic Active Hepatitis
  • Chronic Inflammatory Demyelinating Polyradiculoneuropathy
  • Cogan’s Syndrome
  • Crohn’s Disease, Acute
  • Crohn’s Disease, Maintenance
  • Dermatomyositis
  • Eczema
  • Glomerulonephritis
  • Idiopathic Thrombocytopenic Purpura
  • Inflammatory Bowel Disease
  • Multiple Sclerosis
  • Myasthenia Gravis
  • Myopathy
  • Nephrotic Syndrome
  • Neurosarcoidosis
  • Organ Transplant, Rejection Prophylaxis
  • Systemic Lupus Erythematosus
  • Takayasu’s Arteritis
  • Ulcerative Colitis
  • Uveitis
  • Wegener’s Granulomatosis
  • Disseminated Sclerosis
  • Immune Thrombocytopenia
  • Kidney Transplant Rejection
  • Pericarditis

Contra Indication of Azathioprine

  • Severe infection
  • Severe anemia
  • Decreased Blood Platelets
  • Severe Decrease in White Blood Cells
  • A Blood Clot in a Vein of the Liver
  • Acute Inflammation of the Pancreas
  • Pregnancy
  • Malignant Lymphoma
  • Moderate to Severe Kidney Impairment
  • Thiopurine S-Methyltransferase Deficiency
  • Hepatosplenic T-cell Lymphoma
  • Allergies to Mercaptopurine Analogues

Dosage of Azathioprine

Strengths :  50 mg

 Rheumatoid Arthritis

  • Initial dose: 1 mg/kg (50 to 100 mg) orally or IV per day given in 1 to 2 divided doses
  • Maintenance dose: Lowest effective dose
  • Maximum dose: 2.5 mg/kg orally or IV per day
  • Duration: At least 12 weeks

Crohn’s Disease 

  • 1.5 to 4 mg/kg per day for 10 days up to 52 weeks
  • 1.5 to 4 mg/kg per day for 10 days up to 52 weeks in maintenance dose

Atopic Dermatitis

  • 2.5 mg/kg orally once a day, in the morning, for 3 months

Sarcoidosis

  • Initial dose: 2 mg/kg per day in combination with prednisolone 0.6 to 0.8 mg/kg per day, with prednisolone reduced to 0.1 mg/kg within 2 to 3 months
  • Maintenance dose: 2 mg/kg per day with prednisolone 0.1 mg/kg per day for 21 to 22 months.

Chronic Active Hepatitis

  • Autoimmune hepatitis: 1 to 2 mg/kg per day, concomitantly with prednisolone (5 to 15 mg/day) for a minimum of 1 year (average 5 years)

Uveitis

  • Treatment of choroidal neovascularization: 1 to 1.5 mg/kg orally per day, in combination with prednisolone and cyclosporine

Ulcerative Colitis

  • IV: 20 to 40 mg/kg via IV infusion over 36 hours or 40 mg/kg as three 8-hour infusions over 3 days followed by oral azathioprine
  • Oral: 2 mg/kg orally per day beginning the day after completion of the IV loading dose

Renal Transplant

  • Initial dose: 3 to 5 mg/kg orally or IV once a day, beginning at the time of transplant
  • Maintenance dose: 1 to 3 mg/kg orally or IV once a day

 Pediatric Dose

Atopic Dermatitis

  • Greater than 17 years: 2.5 mg/kg orally once a day, in the morning, for 3 months

Eczema

  • Greater than 6 years: 2.5 to 3.5 mg/kg per day in patients with normal levels of thiopurine methyltransferase

Side Effects of Azathioprine

The most common

Common

Rare

Drug Interactions of Azathioprine

Azathioprine may interact with following drugs, supplyments, & may change the efficacy of drugs

Pregnancy & Lactation of Azathioprine

FDA Pregnancy Category D 

Pregnancy

Animal studies have revealed evidence of teratogenicity. There are no controlled data in human pregnancy. Congenital anomalies, including polydactyly, plagiocephaly, congenital heart disease, hypospadias, and bilateral talipes equinovarus have occurred. Leucopenia and/or thrombocytopenia have been reported in a proportion of neonates whose mothers took azathioprine throughout their pregnancies

Lactation

Studies in women taking azathioprine at doses up to 200 mg per day for immunosuppression in inflammatory bowel disease, systemic lupus erythematosus, or transplantation have found either low or undetectable levels of its active metabolites in milk and infant serum.

References

  1. Azathioprine, Uses, Dosage, Side Effects, Interactions, Pregnancy
Doctor visit helper

Prepare before seeing a doctor

A simple rural-patient checklist to help you explain symptoms clearly, ask better questions, and avoid unsafe self-treatment.

Safety note: This is not a prescription or diagnosis. For severe symptoms, pregnancy danger signs, children with serious illness, chest pain, breathing difficulty, stroke-like weakness, or major injury, seek urgent care.

Which doctor may help?

Start with a registered doctor or the nearest qualified health center.

What to tell the doctor

  • Write when the problem started and how it changed.
  • Bring old prescriptions, investigation reports, and current medicines.
  • Write allergies, pregnancy status, diabetes, kidney/liver disease, and major past illnesses.
  • Bring one family member if the patient is weak, elderly, confused, or a child.

Questions to ask

  • What is the most likely cause of my symptoms?
  • Which danger signs mean I should go to hospital quickly?
  • Which tests are necessary now, and which can wait?
  • How should I take medicines safely and what side effects should I watch for?
  • When should I come for follow-up?

Tests to discuss

  • Vital signs: temperature, pulse, blood pressure, oxygen saturation
  • Basic physical examination by a clinician
  • CBC, urine test, blood sugar, or imaging only when clinically needed

Avoid these mistakes

  • Do not use antibiotics, steroid tablets/injections, or strong painkillers without proper medical advice.
  • Do not hide pregnancy, kidney disease, ulcer, allergy, or blood thinner use.
  • Do not delay emergency care when danger signs are present.

Medicine safety and first-aid guide

This section is for patient education only. It does not replace a doctor, pharmacist, or emergency care.

Safe first steps

  • Avoid heavy lifting, sudden bending, and prolonged bed rest.
  • Use comfortable posture and gentle movement as tolerated.
  • Discuss physiotherapy, X-ray, or MRI only when clinically needed.

OTC medicine safety

  • For mild back pain, pain-relief medicine may be discussed with a doctor or pharmacist.
  • Avoid repeated painkiller use if you have kidney disease, stomach ulcer, uncontrolled blood pressure, or are taking blood thinners.

Avoid these mistakes

  • Do not start antibiotics without a proper medical decision.
  • Do not use steroid tablets or injections casually for quick relief.
  • Do not delay emergency care because of home remedies.

Get urgent help if

  • Back pain with leg weakness, numbness around private area, loss of urine/stool control, fever, cancer history, or major injury needs urgent care.
Medicine names, dose, and timing must be decided by a qualified clinician or pharmacist after checking age, pregnancy, allergy, other diseases, and current medicines.

For rural patients and family caregivers

Patient health record and symptom diary

Write your symptoms, medicines already taken, test results, and questions before visiting a doctor. This note stays on your device unless you print or copy it.

Doctor to discuss: Medicine doctor / pediatrician for children / qualified clinician
Tests to discuss with doctor
  • Temperature chart and hydration assessment
  • CBC with platelet count if fever persists or dengue/other infection is possible
  • Urine test, malaria/dengue tests, chest evaluation, or blood culture only when clinically indicated
Questions to ask
  • What is the most likely cause of my symptoms?
  • Which warning signs mean I should go to emergency care?
  • Which tests are really needed now?
  • Which medicines are safe for my age, pregnancy status, allergy, kidney/liver/stomach condition, and current medicines?
  • Do I need antibiotics, or is this more likely viral?

Emergency warning signs such as chest pain, severe breathing difficulty, sudden weakness, confusion, severe dehydration, major injury, or loss of bladder/bowel control need urgent medical care. Do not wait for online information.

Safe pathway to proper treatment

Care roadmap for: Azathioprine, Uses, Dosage, Side Effects, Interactions, Pregnancy

Use this simple roadmap to understand the next safe steps. It is educational and does not replace examination by a doctor.

Go to emergency care if you notice:
  • Severe or rapidly worsening symptoms
  • Breathing difficulty, chest pain, fainting, confusion, severe weakness, major injury, or severe dehydration
Doctor / service to discuss: Qualified healthcare provider; specialist depends on symptoms and examination.
  1. Step 1

    Check danger signs first

    If danger signs are present, seek emergency care and do not wait for online information.

  2. Step 2

    Record the symptom story

    Write when symptoms started, severity, medicines already taken, allergies, pregnancy status, and test results.

  3. Step 3

    Visit a qualified clinician

    A doctor, nurse, or qualified healthcare provider can examine you and decide which tests or treatment are needed.

  4. Step 4

    Do only useful tests

    Do tests after clinical assessment. Avoid unnecessary tests, random antibiotics, or repeated medicines without diagnosis.

  5. Step 5

    Follow up and return early if worse

    If symptoms worsen, new warning signs appear, or treatment is not helping, return for review quickly.

Rural patient practical tips
  • Take a written symptom diary and all previous prescriptions/test reports.
  • Do not hide medicines already taken, even herbal or over-the-counter medicines.
  • Ask which warning signs mean urgent referral to hospital.

This roadmap is for education. A real diagnosis and treatment plan requires history, examination, and clinical judgment.

RX Patient Help

Ask a health question safely

Write your symptom story. A health professional or site editor can review it before any answer is prepared. This box is not for emergency care.

Emergency first: Severe chest pain, breathing trouble, unconsciousness, stroke signs, severe injury, heavy bleeding, or rapidly worsening symptoms need urgent local medical care now.

Frequently Asked Questions

Is this article a replacement for a doctor?

No. It is educational content only. Patients should consult a qualified clinician for diagnosis and treatment.

When should I seek urgent care?

Seek urgent care for severe symptoms, rapidly worsening condition, breathing difficulty, severe pain, neurological changes, or any emergency warning sign.

References

Add references, clinical guidelines, textbooks, journal articles, or trusted medical sources here. You can edit this area from the RX Article Professional Blocks panel.