IMURAN 50/MG TAB 100/TAB

Indications

Approved Uses

Prevention of rejection in renal homotransplantation; treatment of active rheumatoid arthritis (typically severe disease not adequately controlled with other therapy).

Off-Label Uses

Common off-label uses include inflammatory bowel disease (Crohn’s disease, ulcerative colitis), systemic lupus erythematosus/lupus nephritis, autoimmune hepatitis, myasthenia gravis, vasculitides, dermatomyositis/polymyositis, and some dermatologic autoimmune diseases (e.g., pemphigus).

Dosage & Administration

Dosing by Condition

Renal transplant rejection prophylaxis: Initial 3-5 mg/kg/day PO (often starting at/around transplant), then maintenance ~1-3 mg/kg/day based on response and tolerability.
Rheumatoid arthritis: Start ~1 mg/kg/day PO (often 50-100 mg/day), increase by ~0.5 mg/kg/day every ~4 weeks as needed/tolerated; usual maintenance 1-2.5 mg/kg/day; max ~2.5 mg/kg/day.

Initial Dose

Transplant (adult): 3-5 mg/kg/day PO initially (often 1-3 days pre‑transplant), then maintenance ~1-3 mg/kg/day. Rheumatoid arthritis: 1 mg/kg/day PO (typically 50-100 mg/day) once daily or in 2 divided doses; may increase by 0.5 mg/kg/day every 4 weeks as needed/tolerated.

Maintenance Dose

1-2.5 mg/kg/day

Maximum Dose

Transplant: 5 mg/kg/day PO. Rheumatoid arthritis: 2.5 mg/kg/day PO.

Children's Dosage

Transplant rejection prevention: 1-3 mg/kg/day; IBD (off-label): 1-2.5 mg/kg/day. Dosing is weight-based; use under specialist supervision

Dose Adjustment Notes

Major interaction: if used with allopurinol, reduce azathioprine dose to ~25-33% of usual (i.e., 66-75% reduction) and monitor closely; avoid febuxostat. Reduce dose and/or extend interval in renal impairment; use caution and consider reduction in hepatic impairment. Test TPMT (and where available NUDT15) before therapy-reduced/deficient activity requires substantial dose reduction or alternative therapy.

How to Take

Oral: swallow tablet whole with water; do not chew. May be taken with food/after meals to reduce nausea. If tablets must be split/crushed, minimize exposure to powder (wash hands; caregivers may use gloves).

Side Effects

Common Side Effects

Nausea/vomiting, diarrhea, anorexia; bone marrow suppression (leukopenia, thrombocytopenia, anemia); increased risk of infections; elevated liver enzymes/hepatotoxicity.

Side Effect Frequency

Very common/common: bone marrow suppression (leukopenia; may include anemia/thrombocytopenia), infections, GI upset (nausea/vomiting/diarrhea), and elevated liver enzymes/hepatitis; Uncommon/rare but important: pancreatitis, hypersensitivity reactions, serious hepatotoxicity (including cholestasis/veno-occlusive disease), and malignancy risk (lymphoma and non-melanoma skin cancer) with long-term immunosuppression.

Safety & Warnings

Contraindications

Contraindications: hypersensitivity to azathioprine; pregnancy is contraindicated for rheumatoid arthritis indication; use in patients with known absent TPMT activity is contraindicated/should be avoided due to life-threatening myelotoxicity.

Warnings & Precautions

Monitor CBC frequently (especially early) and LFTs; assess TPMT (and often NUDT15 where available) before/early in therapy; counsel on infection risk and avoidance of live vaccines; counsel sun protection/skin cancer surveillance; adjust/hold therapy for cytopenias or significant hepatotoxicity.

Age Restriction

No absolute minimum age; pediatric use is permitted under specialist supervision with weight-based dosing and close monitoring.

Drug Interactions

Drug Interactions

Key interactions: xanthine oxidase inhibitors (allopurinol/febuxostat) markedly increase toxicity-avoid or reduce azathioprine dose substantially; warfarin effect may be reduced; ACE inhibitors may increase leukopenia risk; aminosalicylates (e.g., sulfasalazine/mesalamine) can increase myelotoxicity; ribavirin increases myelotoxicity; avoid live vaccines due to immunosuppression.

Interaction Severity

"MAJOR/CONTRAINDICATED or AVOID: ["Allopurinol (requires azathioprine dose to ~25-33% and close monitoring)
Febuxostat (avoid-marked toxicity risk)
Live vaccines (avoid during significant immunosuppression)
Ribavirin (increased myelotoxicity risk-avoid/monitor closely)"], "MODERATE (monitor/adjust): ["Warfarin (reduced anticoagulant effect-monitor INR)
ACE inhibitors (increased risk of leukopenia/anemia)
Co-trimoxazole/trimethoprim (additive myelosuppression)
Aminosalicylates e.g., mesalamine/olsalazine/sulfasalazine (TPMT inhibition/additive myelosuppression)
Other immunosuppressants (additive infection/myelosuppression risk)"]

Food Interaction

May be taken with food to reduce GI upset; avoid taking with milk/dairy at the same time (separate by ~1-2 hours) if possible.

Special Populations

Pregnancy

IMURAN should not be used for treating rheumatoid arthritis in pregnant women

Children

Transplant rejection prevention: 1-3 mg/kg/day; IBD (off-label): 1-2.5 mg/kg/day. Dosing is weight-based; use under specialist supervision

Elderly

Standard adult dosing, but monitoring should be considered due to a greater potential for decreased renal function.

Kidney Impairment

Consider dose reduction in renal impairment and use the lowest effective dose with close CBC monitoring; additional caution in severe renal failure/dialysis.

Liver Impairment

No fixed adjustment; use caution and consider dose reduction in hepatic impairment with close LFT/CBC monitoring, and discontinue if significant hepatotoxicity occurs.

Storage & Patient Advice

Missed Dose

Take the missed dose as soon as remembered the same day; if it is close to the next scheduled dose, skip the missed dose and resume the regular schedule; do not double doses.

Stopping the Medicine

Do not discontinue without prescriber direction; abrupt cessation may be appropriate in toxicity, but stopping can precipitate disease flare or transplant rejection, so decisions should be individualized.

Overdose

Overdose may cause early GI symptoms (nausea/vomiting/diarrhea) followed by delayed, potentially severe myelosuppression and hepatotoxicity; management is urgent medical evaluation, supportive care, and prolonged CBC/LFT monitoring (effects can be delayed).

Patient Counseling

Take azathioprine (IMURAN) exactly as prescribed; do not stop without your prescriber. Take with food if it upsets your stomach (no routine need to avoid dairy). Seek urgent advice for signs of infection (fever, chills, sore throat), unusual bruising/bleeding, mouth ulcers, severe nausea/vomiting, abdominal pain (possible pancreatitis), or jaundice/dark urine (possible liver injury). Keep all scheduled blood tests (CBC and LFT monitoring is essential). Avoid live vaccines while on therapy; discuss any vaccines with your clinician. Use sun protection and avoid excessive UV exposure due to increased skin cancer risk. Use effective contraception during treatment; discuss pregnancy/breastfeeding plans with your clinician. Handle tablets carefully (do not crush/chew; if splitting is required, minimize powder contact and wash hands).

Monitoring Requirements

Baseline: CBC with differential/platelets, LFTs, renal function; TPMT (and where available NUDT15) prior to initiation. After start or dose change: CBC and LFTs frequently (e.g., weekly for 4-8 weeks), then every 1-3 months once stable; ongoing clinical monitoring for infection, bleeding, hepatotoxicity, and malignancy/skin cancer.

Pharmacology

Mechanism of Action

Azathioprine is a prodrug converted to 6-mercaptopurine and then thioguanine nucleotides that inhibit de novo purine synthesis and incorporate into nucleic acids, suppressing proliferation/function of T and B lymphocytes (purine antimetabolite; nucleic acid synthesis inhibitor).

Onset of Action

Delayed: clinical benefit typically begins after ~4-8 weeks; full effect may take ~3-6 months (e.g., in rheumatoid arthritis/IBD).

Duration of Effect

Immunosuppressive effect persists while on therapy; after discontinuation, immunosuppressive effects may persist for days to weeks (blood counts may take weeks to recover depending on toxicity).

Half-Life

Azathioprine: ~5-15 minutes; 6-mercaptopurine: ~0.5-2 hours; active thioguanine nucleotide metabolites persist much longer (days; e.g., erythrocyte TGN ~3-13 days).

Bioavailability

Approximately 30-60% (commonly cited mean ~47%, with wide interpatient variability).

Metabolism

Converted non-enzymatically/rapidly to 6-mercaptopurine, then metabolized via TPMT (methylation), xanthine oxidase (inactive 6-thiouric acid), and HGPRT pathway to active thioguanine nucleotides (intracellular).

Excretion

Primarily renal excretion of metabolites; about half of a dose is recovered in urine within 24 hours (mostly as metabolites, minimal unchanged drug).

Protein Binding

Low protein binding, approximately 30%.

Product Information

Available Dosage Forms

Tablet (this SFDA product: 50 mg oral tablet). Azathioprine also exists in some markets as a powder for solution for injection (IV), but that is a different presentation from this registered tablet.

Composition per Dose

Each tablet: 50mg azathioprine

Generic Availability

Yes

OTC Alternatives

No OTC alternative

Primary Use

Immunosuppressant used to prevent organ transplant rejection and treat severe autoimmune conditions such as rheumatoid arthritis

Legal Disclaimer - Al Mujtama Pharmacy

The product information provided is derived from verified pharmaceutical references and is intended for general health education only. It is not a substitute for professional medical advice, diagnosis, or treatment.

Al Mujtama Pharmacy assumes no legal or medical liability for:

• Any therapeutic decision made based on the information displayed without consulting a licensed physician or pharmacist
• Any discrepancy between the information provided and the product's package insert or SFDA guidelines
• Any misuse of medication resulting from personal interpretation of the content displayed

Important notice: Drug formulations and instructions may vary between production batches. Always rely on the leaflet included inside the product packaging you have, and consult your pharmacist or physician before starting, adjusting, or discontinuing any medication.

By using this content, you acknowledge that you have read this disclaimer and agree that Al Mujtama Pharmacy bears no liability arising from reliance on this information as a substitute for direct medical consultation.

Your health is a trust - always consult your doctor first.