Imuran

Imuran (azathioprine) is an immunosuppressive medication indicated for the management of autoimmune disorders and the prevention of organ transplant rejection. As a purine analogue antimetabolite, it modulates the immune system by inhibiting DNA and RNA synthesis, thereby reducing the proliferation of lymphocytes. This agent is commonly prescribed in rheumatology, gastroenterology, and transplant medicine due to its established efficacy and well-characterized safety profile when used under appropriate medical supervision. Proper patient selection, dosing, and monitoring are essential to maximize therapeutic outcomes and minimize risks.

Features

• Active ingredient: Azathioprine
• Available in 25 mg, 50 mg, 75 mg, and 100 mg oral tablets
• Generic and brand-name formulations available
• Requires metabolism to active metabolites (6-mercaptopurine)
• Thiopurine S-methyltransferase (TPMT) testing recommended prior to initiation
• Delayed onset of action; therapeutic effects may take 6–8 weeks

Benefits

• Reduces disease activity in autoimmune conditions such as rheumatoid arthritis, lupus, and inflammatory bowel disease
• Decreases risk of acute and chronic organ transplant rejection
• Allows for reduction in corticosteroid dosing and associated side effects
• Provides long-term disease control with once-daily oral administration
• May help prevent disease progression and tissue damage in chronic inflammatory conditions
• Supported by decades of clinical experience and evidence-based guidelines

Common use

Imuran is primarily used for immunosuppression in solid organ transplantation (kidney, heart, liver) and management of autoimmune disorders including rheumatoid arthritis, systemic lupus erythematosus, pemphigus vulgaris, autoimmune hepatitis, ulcerative colitis, and Crohn’s disease. It may be used as monotherapy or in combination with other immunosuppressive agents depending on the clinical context and treatment goals.

Dosage and direction

Dosage must be individualized based on indication, patient weight, renal function, and TPMT enzyme activity. For transplant patients: Initial dose typically 3–5 mg/kg/day, maintenance dose 1–3 mg/kg/day. For autoimmune diseases: Initial dose 1 mg/kg/day, may increase by 0.5 mg/kg/day at 4-week intervals to maximum 2.5 mg/kg/day. Administer orally once daily or in divided doses, with or after food to minimize gastrointestinal upset. Regular monitoring of complete blood count and liver function is mandatory.

Precautions

Regular hematologic monitoring is essential due to risk of myelosuppression. Monitor for signs of infection. Use with caution in patients with renal impairment (dose reduction required). Avoid live vaccines during therapy. Pregnancy Category D: weigh potential benefits against fetal risks. May increase risk of secondary malignancies with long-term use. Patients should be advised to report any unusual bleeding, bruising, fever, sore throat, or signs of infection promptly.

Contraindications

Hypersensitivity to azathioprine or any component of the formulation. Patients with TPMT deficiency (homozygous) should generally not receive Imuran. Concomitant use with febuxostat. Treatment of rheumatoid arthritis in pregnant women. Patients with previously treated lymphoma or other malignancies unless benefit clearly outweighs risk.

Possible side effect

Common: Nausea, vomiting, diarrhea, leukopenia, thrombocytopenia, rash. Serious: Severe bone marrow suppression (pancytopenia), hepatotoxicity, pancreatitis, increased susceptibility to infections, lymphoma and other malignancies, severe hypersensitivity reactions, alopecia. Gastrointestinal symptoms often diminish with continued therapy or dose reduction.

Drug interaction

Allopurinol, febuxostat (concurrent use contraindicated - requires 75% dose reduction if allopurinol must be used). ACE inhibitors may increase risk of anemia and leukopenia. Warfarin (may reduce anticoagulant effect). Other myelosuppressive agents (additive toxicity). Live vaccines (avoid concomitant use). Aminosalicylate derivatives (e.g., mesalamine, sulfasalazine) may increase myelosuppression risk.

Missed dose

If a dose is missed, take it as soon as remembered unless it is almost time for the next dose. Do not double the dose to make up for a missed dose. Maintain regular dosing schedule to ensure consistent immunosuppression. Contact healthcare provider if multiple doses are missed or if unsure about proper dosing.

Overdose

Symptoms may include nausea, vomiting, diarrhea, and hematologic toxicity (leukopenia, thrombocytopenia, bleeding). Management is supportive with gastric lavage if recent ingestion, hematologic monitoring for at least 4 weeks, and appropriate treatment of complications. Hemodialysis is not effective due to high protein binding. Contact poison control center immediately for guidance.

Storage

Store at controlled room temperature (20-25°C or 68-77°F). Keep container tightly closed. Protect from light and moisture. Keep out of reach of children and pets. Do not use after expiration date. Properly dispose of unused medication according to local regulations.

Disclaimer

This information is for educational purposes only and does not constitute medical advice. Imuran is a prescription medication that should only be used under the supervision of a qualified healthcare professional. Individual response to therapy may vary. Always follow your healthcare provider’s instructions regarding use, monitoring, and management of this medication.

Reviews

Clinical studies and decades of use demonstrate Imuran’s efficacy in maintaining transplant graft survival and controlling autoimmune disease activity. Many clinicians appreciate its predictable pharmacokinetics and established monitoring parameters. Patients often report improved quality of life when autoimmune symptoms are controlled, though some experience gastrointestinal side effects initially. The requirement for regular blood monitoring is noted as a consideration for long-term management. Overall, it remains a cornerstone immunosuppressive therapy in appropriate patient populations.