Plain-language summary, compiled from the cited regulatory records
Azathioprine is an immunosuppressant medication [1]. It belongs to the drug class of other immunosuppressants [1].
Azathioprine is approved for use as an adjunct to prevent organ rejection in kidney transplants [1]. It is also indicated for managing active rheumatoid arthritis, helping to reduce its signs and symptoms [1]. In kidney transplantation, experience with a large number of transplants indicates that patient survival rates over five years can range from 35% to 55%, depending on the donor [1].
In the past 12 months, there have been 4,920 adverse event reports associated with azathioprine [2]. The most frequently reported issues include off-label use, perceived ineffectiveness of the drug, worsening of a condition, maternal exposure during pregnancy, and hypertension [2].
This is not medical advice. Consult a qualified healthcare professional.
GBOfficial regulatory label· revised May 22, 2026[1]
Jayempi is indicated in combination with other immunosuppressive agents for the prophylaxis of transplant rejection in patients receiving allogenic kidney, liver, heart, lung or pancreas transplants. Azathioprine is indicated in immunosuppressive regimens as an adjunct to immunosuppressive agents that form the mainstay of treatment (basis immunosuppression).
Jayempi is used as an immunosuppressant antimetabolite either alone or, more commonly, in combination with other agents (usually corticosteroids) and/ or procedures which influence the immune response. Jayempi is indicated in patients who are intolerant to glucocorticosteroids or if the therapeutic response is inadequate despite treatment with high doses of glucocorticosteroids, in the following diseases: - severe active rheumatoid arthritis (chronic polyarthritis) that cannot be kept under control by less toxic agents (disease-modifying anti-rheumatic - medicinal products – DMARDs) - auto-immune hepatitis - systemic lupus erythematosus - dermatomyositis - polyarteritis nodosa - pemphigus vulgaris and bullous pemphigoid - Behçet’s disease - refractory auto-immune haemolytic anaemia, caused by warm IgG antibodies - chronic refractory idiopathic thrombocytopenic purpura Jayempi is used for the treatment of moderately severe to severe forms of chronic inflammatory bowel disease (IBD) (Crohn’s disease or ulcerative colitis) in patients in whom glucocorticosteroid therapy is necessary, but where glucocorticosteroids are not tolerated, or in whom the disease is untreatable with other common means of first choice.
CACanada· Health Canada
3 products
Uses
CAOfficial regulatory label· revised March 22, 2025[2]
IMURAN (azathioprine Tablets USP) and IMURAN for injection (azathioprine sodium for Injection, Manufacturer’s Standard) is indicated for: • Renal Homotransplantation IMURAN is indicated as an adjunct for the prevention of rejection in renal homotransplantation.
• Rheumatoid Arthritis IMURAN is indicated only in adult patients meeting criteria for classic or definite rheumatoid arthritis as specified by the American Rheumatism Association. IMURAN should be restricted to patients with severe, active and erosive disease not responsive to conventional management including rest, acetylsalicylic acid or other non-steroidal drugs, or with disease-modifying antirheumatic drugs (DMARD’s).
1 Pediatrics Pediatrics (<18 years of age): No data are available to Health Canada; therefore, Health Canada has not authorized an indication for pediatric use. 2 Geriatrics Geriatrics (> 65 years of age): No data are available to Health Canada; therefore, Health Canada has not authorized an indication for geriatric use.
USUnited States· FDA
1 product
Uses
USOfficial regulatory label· revised May 19, 2025[3]
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.
EUEuropean Union· EMA
1 product
Uses
EUOfficial regulatory label· revised April 23, 2026[4]
Transplantation Jayempi is indicated in combination with other immunosuppressive agents for the prophylaxis of transplant rejection in patients receiving allogenic kidney, liver, heart, lung or pancreas transplants. Azathioprine is indicated in immunosuppressive regimens as an adjunct to immunosuppressive agents that form the mainstay of treatment (basis immunosuppression).
Jayempi is used as an immunosuppressant antimetabolite either alone or, more commonly, in combination with other agents (usually corticosteroids) and/ or procedures which influence the immune response. Chronic inflammatory bowel disease (IBD) Jayempi is used for the treatment of moderately severe to severe forms of chronic inflammatory bowel disease (IBD) (Crohn’s disease or ulcerative colitis) in patients in whom glucocorticosteroid therapy is necessary, but where glucocorticosteroids are not tolerated, or in whom the disease is untreatable with other common means of first choice.
Multiple sclerosis (adults only) It is also indicated in adult patients in relapsing multiple sclerosis, if an immunomodulatory therapy is indicated but beta interferon therapy is not possible, or a stable course has been achieved with previous treatment with azathioprine.
Drug interactions
Known interactions involving Azathioprine. Select one for details. This list is informational and not a complete interaction checker.
Showing 240 of 397. Type above to find a specific drug.
Interaction data compiled from DDInter (academic, CC-BY). Severity classification only - this is not a complete interaction checker and not medical advice.
[1]MHRA (UK) · PLGB135810005 · revised May 22, 2026
[2]Health Canada (DPD) · 00004596 · revised March 22, 2025
[3]FDA DailyMed · 040d010a-b1b2-4d… · revised May 19, 2025 [PDF]
[4]European Medicines Agency · EMEA/H/C/005055 · revised April 23, 2026
[5]OpenFDA adverse-event reports (US), 12 months ending June 4, 2026.
Information on this page is compiled from public regulatory records. Drugvu is not affiliated with any regulator or pharmaceutical manufacturer. This is not medical advice. Always consult a qualified healthcare professional.
It is also indicated in adult patients in relapsing multiple sclerosis, if an immunomodulatory therapy is indicated but beta interferon therapy is not possible, or a stable course has been achieved with previous treatment with azathioprine.
Jayempi is indicated for the treatment of generalised myasthenia gravis. Depending on the severity of the disease, Jayempi should be given in combination with glucocorticosteroids because of slow onset of action at the beginning of treatment and the glucocorticosteroid dose should be gradually reduced after several months of treatment.
How to take
GBOfficial regulatory label· revised May 22, 2026[1]
Therapy with Jayempi should be initiated by a physician experienced in the administration and monitoring of immunosuppressive medicinal products. Posology Transplantation Depending on the immunosuppressive regime selected, a dose of up to 5 mg/kg body weight/day may be given on the first day of therapy.
The maintenance dose can range from 1-4 mg/kg body weight/day and must be adjusted according to the clinical requirements and haematological tolerance. Azathioprine therapy should be maintained indefinitely, even if only low doses are necessary, because of the risk of graft rejection.
Multiple sclerosis (adults only) The usual dose for the treatment of relapsing forms of multiple sclerosis is between 2 and 3 mg/kg body weight/day. A treatment duration of more than 1 year may be required until manifestation of the effect, and at least 2 years may be needed until the disease is actually under control.
Myasthenia gravis The recommended dose for the treatment of myasthenia gravis is 2 mg/kg to 3 mg/kg body weight/day. Treatment success usually occurs 2 to 6 months after the start of treatment at the earliest. Depending on the severity of the disease, Jayempi should be given in combination with glucocorticosteroids at the start of treatment because of the slow onset of the effect.
The dose of glucocorticosteroids can be gradually reduced over several months. Treatment with Jayempi should be continued for at least 2 to 3 years. 5 mg/kg body weight/day and the maintenance dose is up to 2 mg/kg body weight/day. Dose in other conditions In general, the starting dose is 1 to 3 mg/kg body weight/day and should be adjusted according to the clinical response (which may not be evident for weeks or months) and haematological tolerance.
When therapeutic response is evident, consideration should be given to reducing the maintenance dose to the lowest level compatible with the maintenance of that response. If no improvement occurs in the patient's condition within 3 to 6 months, consideration should be given to withdrawing the medicinal product.
The maintenance dose required may range from less than 1 mg/kg/body weight/day to 3 mg/kg/body weight/day depending on the clinical condition being treated and the individual patient response, including haematological tolerance. However, in patients with IBD, a treatment duration of at least 12 months should be considered, whereby a response to treatment may only be recognisable clinically after three to four months.
5). The table below shows, for a range of age, weight and doses, the dose (mg) to volume (ml) conversion using the two oral syringes. 1 ml (1mg) graduations. 5mg) graduations (shaded cells). Special populations Paediatric population Transplantation The posology in paediatric population is the same as in adults.
Myasthenia gravis The posology in paediatric population is the same as in adults. Chronic active auto-immune hepatitis The posology in paediatric population is the same as in adults. Dose in other conditions The posology in paediatric population is the same as in adults.
Juvenile idiopathic arthritis The safety and efficacy of Jayempi in children (0 to 16 years) have not yet been established. No data are available. Multiple sclerosis There is no relevant use of Jayempi in the paediatric population for the indication of multiple sclerosis.
Overweight children Children considered to be overweight may require doses at the higher end of the dose range. 2). 2). The dose used should be at the lower end of the normal range. For controls of blood count, see section
This is not medical advice. Consult a qualified healthcare professional.
Side effects & warnings
GBOfficial regulatory label· Adverse reactions· revised May 22, 2026[1]
Summary of the safety profile The most important adverse reactions include bone marrow depression, most frequently expressed as leukopenia and thrombocytopenia; viral, fungal and bacterial infections; life-threatening liver injury; hypersensitivity, Stevens-Johnson syndrome and toxic epidermal necrolysis.
Tabulated list of adverse reactions The adverse reactions are listed below according to system organ class and frequency. The frequencies are defined as follows: very common (≥ 1/10), common (≥ 1/100 to < 1/10), uncommon (≥ 1/1,000 to < 1/100), rare (≥ 1/10,000 to < 1/1,000), very rare (< 1/10,000) (including isolated cases), not known (cannot be estimated from the available data).
4) Neoplasms benign, malignant and unspecified (incl. 4). 4). The increased risk of developing non-Hodgkin’s lymphomas in immunosuppressed rheumatoid arthritis patients compared with the general population appears to be related at least in part to the disease itself.
There have been rare reports of acute myeloid leucaemia and myelodysplasia (some in association with chromosomal abnormalities). Blood and lymphatic system disorders The most common adverse reaction of azathioprine is a dose-related, generally reversible, depression of bone marrow function, most frequently expressed as leucopenia, but also sometimes as thrombocytopenia and anaemia, and rarely as agranulocytosis, pancytopenia and aplastic anaemia.
5). Reversible, dose-related macrocytosis and increase in red cell haemoglobin content have occurred in association with azathioprine therapy. Megaloblastic bone marrow changes have also been observed but severe megaloblastic anaemia and erythroid hypoplasia are rare.
Immune system disorders Several different clinical syndromes, which appear to be idiosyncratic manifestations of hypersensitivity, have been described occasionally following administration of azathioprine. Clinical features include general malaise, dizziness, nausea, vomiting, diarrhoea, fever, rigors, exanthema, erythema nodosum, vasculitis, myalgia, arthralgia, hypotension, cardiac dysfunction, renal dysfunction, hepatic dysfunction and cholestasis.
In many cases, re-challenge has confirmed an association with azathioprine. Hypersensitivity reactions and other marked underlying pathology may have contributed to the very rare deaths reported. Immediate withdrawal of azathioprine and institution of circulatory support where appropriate have led to recovery in the majority of cases.
Following a hypersensitivity reaction to azathioprine, the necessity for continued administration of azathioprine should be carefully considered on an individual basis. Gastrointestinal disorders […]
GBOfficial regulatory label· Warnings and precautions· revised May 22, 2026[1]
4. 4). Patients with TPMT deficiency Patients with inherited little or no thiopurine S-methyltransferase (TPMT) activity are at increased risk for severe azathioprine toxicity from conventional doses of azathioprine and generally require substantial dose reduction.
2). Most patients with heterozygous TPMT deficiency can tolerate recommended azathioprine doses, but some may require dose reduction. 2). 4). These patients generally require dose reduction; particularly those being NUDT15 variant homozygotes.
Genotypic testing of NUDT15 variants may be considered before initiating azathioprine therapy. 4). Method of administration Jayempi is for oral use and requires redispersing by shaking prior to dosing. To measure the dose in ml in accordance with the prescribed posology, two oral syringes are included in the pack; 3 ml and 10 ml.
5 mg) steps respectively. The healthcare professional should advise the patient or carer which syringe to use to ensure that the correct volume is administered. In adults without swallowing difficulties, solid oral formulations may be more appropriate and convenient.
Jayempi should be taken at least 1 hour before or 2 hours after a meal or milk. Water should be taken after each dose in order to ensure accurate and consistent dose delivery to the stomach. 1. 6). 4 Special warnings and precautions for use Monitoring Therapy with Jayempi in pre-existing, severe infections, in severe disorders of the liver and bone marrow function and in the presence of pancreatitis should only be initiated subject to a careful benefit/risk analysis and the precautions specified below.
Special attention should be given to monitoring the blood count. If necessary, the maintenance dose should be reduced as much as possible, provided there is clinical response. Azathioprine should only be prescribed if the patient can be adequately monitored for haematological and hepatic effects throughout the duration of therapy.
During the first 8 weeks of treatment, a complete blood count, including platelet count must be performed at least once weekly. It should be controlled more frequently: - if high doses are used - in elderly patients - if renal function is impaired.
2) - if hepatic function is impaired. 2). 8). This is particularly important in patients with severe impaired liver function and azathioprine should only be used after a careful benefit/risk analysis. Azathioprine is hepatotoxic, thus regular liver function tests should be repeated during the treatment.
This is not medical advice. Consult a qualified healthcare professional.
Who should not take it
GBOfficial regulatory label· Contraindications· revised May 22, 2026[1]
1. 6).
This is not medical advice. Consult a qualified healthcare professional.
How to take
CAOfficial regulatory label· revised March 22, 2025[2]
2 Recommended Dose and Dosage Adjustment Renal Homotransplantation The dose of IMURAN (azathioprine) required to prevent rejection and minimize toxicity will vary with individual patients; this necessitates careful management. The initial dose is usually 3-5 mg/kg daily, beginning at the time of transplant.
IMURAN is usually given as a single daily dose on the day of, and in a minority of cases one to three days before, transplantation. IMURAN is often initiated with the intravenous administration of the sodium salt, with subsequent use of tablets (at the same dose level) after the post-operative period.
Intravenous administration of the sodium salt is indicated only in patients unable to tolerate oral medications. Dose reduction to maintenance levels of 1-3 mg/kg daily is usually possible. The dose of IMURAN should not be increased to toxic levels because of threatened rejection.
Discontinuation may be necessary for severe hematologic or other toxicity, even if rejection of the homograft may be a consequence of drug withdrawal. Rheumatoid Arthritis IMURAN is usually given on a daily basis. 0 mg/kg (50-100 mg) given as a single dose or on a twice daily schedule.
The dose may be increased, beginning at six to eight weeks and thereafter by steps at four-week intervals, if there are no serious toxicities and if initial response is unsatisfactory. 5 mg/kg/day. Therapeutic response occurs after several weeks of treatment, usually six to eight; an adequate trial should be a minimum of 12 weeks.
Patients not improved after twelve weeks can be considered refractory. IMURAN may be continued long-term in patients with clinical response, but patients should be monitored carefully, and gradual dosage reduction should be attempted to reduce risk of toxicities.
5 mg/kg or approximately 25 mg daily every four weeks, while other therapy is kept constant. The optimum duration of maintenance IMURAN has not been determined. IMURAN can be discontinued abruptly, but delayed effects are possible. Rest, physiotherapy and salicylates should be continued while IMURAN is given, but it may be possible to reduce the dose of corticosteroids in patients on IMURAN.
Use in Renal Dysfunction Relatively oliguric patients, especially those with tubular necrosis in the immediate post-cadaveric transplant period, may have delayed clearance of IMURAN or its metabolites, or be particularly sensitive to this drug, and are usually given lower doses.
Imuran® 50mg Tablets / Imuran® 50mg Vial / Azathioprine Page 7 of 37 Patients with NUDT15 variant Patients with inherited mutated NUDT15 gene are at increased risk for severe 6- mercaptopurine toxicity (See 7 Patients with NUDT15 variant).
These patients generally require dose reduction; particularly those being NUDT15 variant homozygotes (See 7 Patients with NUDT15 variant). Genotypic testing of NUDT15 variants may be considered before initiating 6-mercaptopurine therapy.
In any case, close monitoring of blood counts is necessary. 3 Reconstitution Parenteral Products: Table - Reconstitution Vial Size Volume of Diluent to be Added to Vial Approximate Available Volume Nominal Concentration per mL 50 mg 5 ml 5 ml 10 mg/ml SHAKE UNTIL COMPLETE DISSOLUTION.
No antimicrobial preservative is included. Therefore, reconstitution and dilution must be carried out under full aseptic conditions, preferably immediately before use. Any unused solution should be discarded (see 11 STORAGE, STABILITY AND DISPOSAL).
Intravenous Infusion:
Further dilution into sterile saline is usually made for infusion. The final volume depends on the time for the infusion, usually 30-60 minutes, but as short as five minutes and as long as eight hours for the daily dose. As with all parenteral drug products, intravenous admixtures should be inspected visually for clarity, particulate matter, precipitate, discolouration and leakage prior to administration whenever solution and container permit.
Solutions showing haziness, particulate matter, precipitate, discolouration or leakage should not be used. Discard unused portion (see 11 STORAGE, STABILITY AND DISPOSAL). 4 Administration IMURAN® for Injection ONLY: Imuran® 50mg Tablets / Imuran® 50mg Vial / Azathioprine Page 8 of 37 Parenteral Administration FOR INTRAVENOUS USE ONLY.
A 50mg vial should be reconstituted with 5 to 15 mL Sterile Water for Injection, however to obtain a nominal concentration of 10mg/mL, 5mL of Sterile Water for Injection should be used. Once the Sterile Water for Injection has been added, swirl until a clear solution results.
This solution has a pH of approximately 10-12. No antimicrobial preservative is included. Therefore reconstitution and dilution must be carried out under full aseptic conditions, preferably immediately before use. Any unused solution should be discarded.
Further dilution into sterile saline is usually made for infusion; the final volume depends on time for the infusion, usually 30-60 minutes but as short as five minutes and as long as eight hours for the daily dose.
This is not medical advice. Consult a qualified healthcare professional.
Side effects & warnings
CAOfficial regulatory label· Adverse reactions· revised March 22, 2025[2]
). Fungal, viral, bacterial and protozoal infections may be fatal and should be treated vigorously. Reduction of azathioprine dosage and/or use of other drugs should be considered. Infection with varicella zoster virus (VZV; chickenpox and herpes zoster) may become severe during the administration of immunosuppressants.
Caution should be exercised especially with respect to the following:
Before starting the administration of immunosuppressants, the prescriber should check to see if the patient has a history of VZV. Serologic testing may be useful in determining previous exposure. Patients who have no history of exposure should avoid contact with individuals with chickenpox or herpes zoster.
If the patient is exposed to VZV, special care must be taken to avoid patients developing chickenpox or herpes zoster, and passive immunisation with varicella-zoster immunoglobulin (VZIG) may be considered. If the patient is infected with VZV, appropriate measures should be taken, which may include antiviral therapy and supportive care.
Hypersensitivity Patients with a history of hypersensitivity reaction to 6-mercaptopurine should not be prescribed azathioprine. Imuran® 50mg Tablets / Imuran® 50mg Vial / Azathioprine Page 13 of 37 Macrophage activation syndrome Macrophage activation syndrome (MAS) is a known, life-threatening disorder that may develop in patients with autoimmune conditions, in particular with inflammatory bowel disease (IBD), and there could potentially be an increased susceptibility for developing the condition with the use of azathioprine.
If MAS occurs, or is suspected, evaluation and treatment should be started as early as possible, and treatment with azathioprine should be discontinued. Physicians should be attentive to symptoms of infection such as EBV and cytomegalovirus (CMV), as these are known triggers for MAS.
Neuromuscular agents Special care is necessary when azathioprine is given concomitantly with neuromuscular acting agents like tubocurarine or succinylcholine (see
CAOfficial regulatory label· Warnings and precautions· revised March 22, 2025[2]
1 Pregnant Women 09/2023 TABLE OF CONTENTS Sections or subsections that are not applicable at the time of authorization are not listed. RECENT MAJOR LABEL CHANGES .............................................................................
2 TABLE OF CONTENTS ............................................................................................... 2 PART I: HEALTH PROFESSIONAL INFORMATION ...................................................... 4 1 INDICATIONS ...............................................................................................
This is not medical advice. Consult a qualified healthcare professional.
Who should not take it
CAOfficial regulatory label· Contraindications· revised March 22, 2025[2]
IMURAN is contraindicated in patients who are hypersensitive to this drug or to any ingredient in the formulation, including any non-medicinal ingredient, or component of the container. For a complete listing, see 6 DOSAGE FORMS, STRENGTHS, COMPOSITION AND PACKAGING.
The combined use of azathioprine tablets with disease modifying anti-rheumatic drugs (DMARDs) has not been studied for either added benefit or unexpected adverse effects. The use of azathioprine tablets with these agents cannot be recommended.
How to take
USOfficial regulatory label· revised May 19, 2025[3]
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.
Discontinuation may be necessary for severe hematologic or other toxicity, even if rejection of the homograft may be a consequence of drug withdrawal. Rheumatoid Arthritis Azathioprine tablets are usually given on a daily basis. 0 mg/kg (50 to 100 mg) given as a single dose or on a twice-daily schedule.
The dose may be increased, beginning at 6 to 8 weeks and thereafter by steps at 4-week intervals, if there are no serious toxicities and if initial response is unsatisfactory. 5 mg/kg per day. Therapeutic response occurs after several weeks of treatment, usually 6 to 8; an adequate trial should be a minimum of 12 weeks.
Patients not improved after 12 weeks can be considered refractory. Azathioprine tablets may be continued long-term in patients with clinical response, but patients should be monitored carefully, and gradual dosage reduction should be attempted to reduce risk of toxicities.
5 mg/kg or approximately 25 mg daily every 4 weeks while other therapy is kept constant. The optimum duration of maintenance azathioprine tablets has not been determined. Azathioprine tablets can be discontinued abruptly, but delayed effects are possible.
Patients with TPMT and/or NUDT15 Deficiency Consider testing for TPMT and NUDT15 deficiency in patients who experience severe bone marrow toxicities. Early drug discontinuation may be considered in patients with abnormal CBC results that do not respond to dose reduction (see CLINICAL PHARMACOLOGY , WARNINGS: Cytopenias , and PRECAUTIONS: Laboratory Tests ).
Homozygous deficiency in either TPMT or NUDT15 Because of the risk of increased toxicity, consider alternative therapies for patients who are known to have TPMT or NUDT15 deficiency (see CLINICAL PHARMACOLOGY , WARNINGS: Cytopenias , and PRECAUTIONS: Laboratory Tests ).
Heterozygous deficiency in TPMT and/or NUDT15 Because of the risk of increased toxicity, dosage reduction is recommended in patients known to have heterozygous deficiency of TPMT or NUDT15. Patients who are heterozygous for both TPMT and NUDT15 deficiency may require more substantial dosage reductions (see CLINICAL PHARMACOLOGY , WARNINGS: Cytopenias , and PRECAUTIONS: Laboratory Tests ).
Use in Renal Dysfunction Relatively oliguric patients, especially those with tubular necrosis in the immediate postcadaveric transplant period, may have delayed clearance of azathioprine tablets or its metabolites, may be particularly sensitive to this drug, and are usually given lower doses.
Procedures for proper handling and disposal of this immunosuppressive antimetabolite drug should be considered. Several guidelines on this subject have been published. 15-21 There is no general agreement that all of the procedures recommended in the guidelines are necessary or appropriate.
This is not medical advice. Consult a qualified healthcare professional.
Most-reported reactions to the US regulator (12 mo to June 4, 2026): 4,920 reports total. [5]
Off Label Use 1,180
Drug Ineffective 699
Condition Aggravated 521
Maternal Exposure During Pregnancy 401
Hypertension 356
Intentional Product Use Issue 356
Headache 351
Treatment Failure 345
Arthralgia 341
Diarrhoea 336
Fatigue 329
Dyspnoea 328
Side effects & warnings
USOfficial regulatory label· Adverse reactions· revised May 19, 2025[3]
ADVERSE REACTIONS
The principal and potentially serious toxic effects of azathioprine tablets are hematologic and gastrointestinal. The risks of secondary infection and malignancy are also significant (see WARNINGS ). The frequency and severity of adverse reactions depend on the dose and duration of azathioprine tablets as well as on the patient’s underlying disease or concomitant therapies.
The incidence of hematologic toxicities and neoplasia encountered in groups of renal homograft recipients is significantly higher than that in studies employing azathioprine tablets for rheumatoid arthritis.
The relative incidences in clinical studies are summarized below:
Toxicity Renal Homograft Rheumatoid Arthritis * Data on the rate and risk of neoplasia among persons with rheumatoid arthritis treated with azathioprine are limited. The incidence of lymphoproliferative disease in patients with RA appears to be significantly higher than that in the general population.
8 cases per 1000 patient-years of follow-up in those not receiving azathioprine. , alkylating agents) received by patients treated with azathioprine cannot be determined. 8% Hematologic Leukopenia and/or thrombocytopenia are dose-dependent and may occur late in the course of therapy with azathioprine tablets.
Dose reduction or temporary withdrawal may result in reversal of these toxicities. Infection may occur as a secondary manifestation of bone marrow suppression or leukopenia, but the incidence of infection in renal homotransplantation is 30 to 60 times that in rheumatoid arthritis.
Anemias, including macrocytic anemia and/or bleeding have been reported. Patients with low or absent TPMT or NUDT15 activity are at increased risk for severe, life-threatening myelosuppression from azathioprine (see CLINICAL PHARMACOLOGY , WARNINGS: Cytopenias and PRECAUTIONS: Laboratory Tests , DOSAGE AND ADMINISTRATION ).
Gastrointestinal Nausea and vomiting may occur within the first few months of therapy with azathioprine tablets, and occurred in approximately 12% of 676 rheumatoid arthritis patients. The frequency of gastric disturbance often can be reduced by administration of the drug in divided doses and/or after meals.
However, in some patients, nausea and vomiting may be severe and may be accompanied by symptoms such as diarrhea, fever, malaise, and myalgias (see PRECAUTIONS ). Vomiting with abdominal pain may occur rarely with a hypersensitivity pancreatitis.
Hepatotoxicity manifest by elevation of serum alkaline phosphatase, bilirubin, and/or serum transaminases is known to occur following azathioprine use, primarily in allograft recipients. Hepatotoxicity has been uncommon (less than 1%) in rheumatoid arthritis patients.
Hepatotoxicity following transplantation most often occurs within 6 months of transplantation and is generally reversible after interruption of azathioprine tablets. A rare, but life-threatening hepatic veno-occlusive disease associated with chronic administration of azathioprine has been described in transplant patients and in one patient receiving azathioprine tablets for panuveitis.
11, 12, 13 Periodic measurement of serum transaminases, alkaline phosphatase, and bilirubin is indicated for early detection of hepatotoxicity. If hepatic veno-occlusive disease is clinically suspected, azathioprine tablets should be permanently withdrawn.
Others Additional side effects of low frequency have been reported. These include skin rashes, alopecia, fever, arthralgias, diarrhea, steatorrhea, negative nitrogen balance, reversible interstitial pneumonitis, hepatosplenic T-cell lymphoma (see Warnings - Malignancy ), and Sweet’s Syndrome ( acute febrile neutrophilic dermatosis ).
Postmarketing Experience The following adverse reactions have been identified during postapproval use of azathioprine tablets. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a casual relationship to drug exposure.
intrahepatic cholestasis of pregnancy (see WARNINGS, Pregnancy ).
USOfficial regulatory label· Warnings and precautions· revised May 19, 2025[3]
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. Post-transplant Renal transplant patients are known to have an increased risk of malignancy, predominantly skin cancer and reticulum cell or lymphomatous tumors.
The risk of post-transplant lymphomas may be increased in patients who receive aggressive treatment with immunosuppressive drugs, including azathioprine. Therefore, immunosuppressive drug therapy should be maintained at the lowest effective levels.
Rheumatoid Arthritis Information is available on the risk of malignancy with the use of azathioprine in rheumatoid arthritis (see ADVERSE REACTIONS ). It has not been possible to define the precise risk of malignancy due to azathioprine.
The data suggest the risk may be elevated in patients with rheumatoid arthritis, though lower than for renal transplant patients. However, acute myelogenous leukemia as well as solid tumors have been reported in patients with rheumatoid arthritis who have received azathioprine.
Inflammatory Bowel Disease Postmarketing cases of hepatosplenic T-cell lymphoma (HSTCL), a rare type of T-cell lymphoma, have been reported in patients treated with azathioprine. These cases have had a very aggressive disease course and have been fatal.
The majority of reported cases have occurred in patients with Crohn's disease or ulcerative colitis and the majority were in adolescent and young adult males. Some of the patients were treated with azathioprine as monotherapy and some had received concomitant treatment with a TNFα blocker at or prior to diagnosis.
The safety and efficacy of azathioprine for the treatment of Crohn's disease and ulcerative colitis have not been established. Cytopenias Severe leukopenia, thrombocytopenia, anemias including macrocytic anemia, and/or pancytopenia may occur in patients being treated with azathioprine.
This is not medical advice. Consult a qualified healthcare professional.
Who should not take it
USOfficial regulatory label· Contraindications· revised May 19, 2025[3]
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.
This is not medical advice. Consult a qualified healthcare professional.
Myasthenia gravis Jayempi is indicated for the treatment of generalised myasthenia gravis. Depending on the severity of the disease, Jayempi should be given in combination with glucocorticosteroids because of slow onset of action at the beginning of treatment and the glucocorticosteroid dose should be gradually reduced after several months of treatment.
3 Other conditions Jayempi is indicated in patients who are intolerant to glucocorticosteroids or if the therapeutic response is inadequate despite treatment with high doses of glucocorticosteroids, in the following diseases: - severe active rheumatoid arthritis (chronic polyarthritis) that cannot be kept under control by less toxic agents (disease-modifying anti-rheumatic -medicinal products – DMARDs) - auto-immune hepatitis - systemic lupus erythematosus - dermatomyositis - polyarteritis nodosa - pemphigus vulgaris and bullous pemphigoid - Behçet’s disease - refractory auto-immune haemolytic anaemia, caused by warm IgG antibodies - chronic refractory idiopathic thrombocytopenic purpura
How to take
EUOfficial regulatory label· revised April 23, 2026[4]
Treatment should be initiated by a physician experienced in the administration and monitoring of immunosuppressive medicinal products. Posology Transplantation Depending on the immunosuppressive regime selected, a dose of up to 5 mg/kg body weight/day may be given on the first day of therapy.
The maintenance dose can range from 1-4 mg/kg body weight/day and must be adjusted according to the clinical requirements and haematological tolerance. Azathioprine therapy should be maintained indefinitely, even if only low doses are necessary, because of the risk of graft rejection.
Multiple sclerosis (adults only) The usual dose for the treatment of relapsing forms of multiple sclerosis is between 2 and 3 mg/kg body weight/day. A treatment duration of more than 1 year may be required until manifestation of the effect, and at least 2 years may be needed until the disease is actually under control.
Myasthenia gravis The recommended dose for the treatment of myasthenia gravis is 2 mg/kg to 3 mg/kg body weight/day. Treatment success usually occurs 2 to 6 months after the start of treatment at the earliest. Depending on the severity of the disease, Jayempi should be given in combination with glucocorticosteroids at the start of treatment because of the slow onset of the effect.
The dose of glucocorticosteroids can be gradually reduced over several months. Treatment with Jayempi should be continued for at least 2 to 3 years. 5 mg/kg body weight/day and the maintenance dose is up to 2 mg/kg body weight/day. 4 Dose in other conditions In general, the starting dose is 1 to 3 mg/kg body weight/day and should be adjusted according to the clinical response (which may not be evident for weeks or months) and haematological tolerance.
When therapeutic response is evident, consideration should be given to reducing the maintenance dose to the lowest level compatible with the maintenance of that response. If no improvement occurs in the patient's condition within 3 to 6 months, consideration should be given to withdrawing the medicinal product.
The maintenance dose required may range from less than 1 mg/kg body weight/day to 3 mg/kg body weight/day depending on the clinical condition being treated and the individual patient response, including haematological tolerance. However, in patients with IBD, a treatment duration of at least 12 months should be considered, whereby a response to treatment may only be recognisable clinically after three to four months.
5). The table below shows, for a range of age, weight and doses, the dose (mg) to volume (ml) conversion using the two oral syringes. 1 ml (1 mg) graduations. 5 mg) graduations (shaded cells). 2). The dose used should be at the lower end of the normal range.
For controls of blood count, see section
This is not medical advice. Consult a qualified healthcare professional.
Side effects & warnings
EUOfficial regulatory label· Adverse reactions· revised April 23, 2026[4]
Summary of the safety profile The most frequently reported adverse reactions include bone marrow depression, most frequently expressed as leukopenia and thrombocytopenia as well as viral, fungal and bacterial infections after using azathioprine in combination with other immunosuppressants.
The most serious adverse reactions are usually rare to very rare and include life-threatening liver injury , neoplasms including hepatosplenic T-cell lymphoma, hypersensitivity, Stevens-Johnson syndrome and toxic epidermal necrolysis.
Tabulated list of adverse reactions The adverse reactions are listed below according to system organ class and frequency. The frequencies are defined as follows: very common (≥ 1/10), common (≥ 1/100 to < 1/10), uncommon (≥ 1/1 000 to < 1/100), rare (≥ 1/10 000 to < 1/1 000), very rare (< 1/10 000), not known (cannot be estimated from the available data).
Within each frequency grouping, adverse reactions are presented in the order of decreasing seriousness. 4) Neoplasms benign, malignant and unspecified (incl. 4). 4). The increased risk of developing non-Hodgkin’s lymphomas in immunosuppressed rheumatoid arthritis patients compared with the general population appears to be related at least in part to the disease itself.
There have been rare reports of acute myeloid leukaemia and myelodysplasia (some in association with chromosomal abnormalities). Blood and lymphatic system disorders The most common adverse reaction of azathioprine is a dose-related, generally reversible, depression of bone marrow function, most frequently expressed as leukopenia, but also sometimes as thrombocytopenia and anaemia, and rarely as agranulocytosis, pancytopenia and aplastic anaemia.
5). Reversible, dose-related macrocytosis and increase in red cell haemoglobin content have occurred in association with azathioprine therapy. Megaloblastic bone marrow changes have also been observed but severe megaloblastic anaemia and erythroid hypoplasia are rare.
Immune system disorders Several different clinical syndromes, which appear to be idiosyncratic manifestations of hypersensitivity, have been described occasionally following administration of azathioprine. Clinical features include general malaise, dizziness, nausea, vomiting, diarrhoea, fever, rigors, exanthema, erythema nodosum, vasculitis, myalgia, arthralgia, hypotension, cardiac dysfunction, renal dysfunction, hepatic dysfunction and cholestasis.
In many cases, re-challenge has confirmed an association with azathioprine. Hypersensitivity reactions and other marked underlying pathology may have contributed to the very rare deaths reported. Immediate withdrawal of azathioprine and institution of circulatory support where appropriate have […]
EUOfficial regulatory label· Warnings and precautions· revised April 23, 2026[4]
4. 4). Patients with TPMT deficiency Patients with inherited little or no thiopurine S-methyltransferase (TPMT) activity are at increased risk for severe azathioprine toxicity from conventional doses of azathioprine and generally require substantial dose reduction.
2). Most patients with heterozygous TPMT deficiency can tolerate recommended azathioprine doses, but some may require dose reduction. 2). 4). These patients generally require dose reduction; particularly those being NUDT15 variant homozygotes.
Genotypic testing of NUDT15 variants may be considered before initiating azathioprine therapy. 4). Paediatric population Juvenile idiopathic arthritis The safety and efficacy of Jayempi in children and adolescents from 0 to 16 years have not yet been established.
No data are available. Multiple sclerosis There is no relevant use of Jayempi in the paediatric population for the indication of multiple sclerosis. Other conditions The posology in paediatric population is the same as in adults. Overweight children Children considered to be overweight may require doses at the higher end of the dose range.
2). Method of administration Jayempi is for oral use and requires redispersing by shaking prior to dosing. To measure the dose in ml in accordance with the prescribed posology, two oral syringes are included in the pack; 3 ml and 10 ml.
5 mg) steps respectively. The healthcare professional should advise the patient or carer which syringe to use to ensure that the correct volume is administered. In adults without swallowing difficulties, solid oral formulations may be more appropriate and convenient.
Jayempi should be taken at least 1 hour before or 2 hours after a meal or milk. Water should be taken after each dose in order to ensure accurate and consistent dose delivery to the stomach. Precaution to be taken before manipulating or administering the product Anyone handling Jayempi should wash their hands before and after administering a dose.
To decrease the risk of exposure, parents and care givers should wear disposable gloves when handling Jayempi. Contact with skin or mucous membrane must be avoided. If Jayempi comes into contact with skin or mucosa, it should be washed immediately and thoroughly with soap and water.
This is not medical advice. Consult a qualified healthcare professional.
Who should not take it
EUOfficial regulatory label· Contraindications· revised April 23, 2026[4]
1. 5). 6).
This is not medical advice. Consult a qualified healthcare professional.
More frequent tests are recommended in patients with liver disease and in those who may be undergoing therapy with a possible hepatotoxic adverse reaction. Cases of non-cirrhotic portal hypertension/portosinusoidal vascular disease have been reported.
8). The patients should be informed about the symptoms of liver injury and advised to contact their doctor immediately if these occur. The frequency of blood counts may be reduced after 8 weeks and be repeated monthly or at least at intervals of no longer than 3 months (maximum quarterly).
At the first sign of an abnormal change in the blood count, treatment should be discontinued immediately because the number of leucocytes and platelets may continue to decrease after the end of treatment. Patients receiving azathioprine must be advised to inform their doctor immediately about any evidence of infection, unexpected bruising or bleeding or other signs of myelosuppression.
Myelosuppression is reversible if azathioprine is discontinued promptly. Thiopurine methyltransferase (TPMT) About 10% of patients have decreased activity of the enzyme thiopurine methyltransferase (TPMT) as a result of genetic polymorphism.
Especially in homozygous individuals, the degradation of azathioprine is impaired, so there is a higher risk of myelotoxic effects. g. 5). 8). Testing for TPMT deficiency is recommended before treatment, in particular for azathioprine therapy in high doses as well as with rapid deterioration of the blood count.
Patients with the NUDT15 variant Patients with inherited mutated NUDT15 gene are at increased risk of severe azathioprine toxicity, […]
2 Clinical Trial Adverse Reactions ........................................................... 3 Less Common Clinical Trial Adverse Reactions .................................... 5 Post-Market Adverse Reactions...........................................................
1 Mechanism of Action ..................................................................... 2 Pharmacodynamics........................................................................ 3 Pharmacokinetics ..........................................................................
21 11 STORAGE, STABILITY AND DISPOSAL ......................................................... 23 12 SPECIAL HANDLING INSTRUCTIONS ........................................................... 23 PART II: SCIENTIFIC INFORMATION .......................................................................
24 13 PHARMACEUTICAL INFORMATION ............................................................ 24 14 CLINICAL TRIALS ........................................................................................ 1 Clinical Trial by Indication ..............................................................
30 Imuran® 50mg Tablets / Imuran® 50mg Vial / Azathioprine Page 4 of 37 PART I: HEALTH PROFESSIONAL INFORMATION 1 INDICATIONS IMURAN (azathioprine Tablets USP) and IMURAN for injection (azathioprine sodium for Injection, Manufacturer’s Standard) is indicated for: • Renal Homotransplantation IMURAN is indicated as an adjunct for the prevention of rejection in renal homotransplantation.
• Rheumatoid Arthritis IMURAN is indicated only in adult patients meeting criteria for classic or definite rheumatoid arthritis as specified by the American Rheumatism Association. IMURAN should be restricted to patients with severe, active and erosive disease not responsive to conventional management including rest, acetylsalicylic acid or other non-steroidal drugs, or with disease-modifying antirheumatic drugs (DMARD’s).
1 Pediatrics Pediatrics (<18 years of age): No data are available to Health Canada; therefore, Health Canada has not authorized an indication for pediatric use. 2 Geriatrics Geriatrics (> 65 years of age): No data are available to Health Canada; therefore, Health Canada has not authorized an indication for geriatric use.
2 CONTRAINDICATIONS IMURAN is contraindicated in patients who are hypersensitive to this drug or to any ingredient in the formulation, including any non-medicinal ingredient, or component of the container. For a complete listing, see 6 DOSAGE FORMS, […]
Severe bone marrow suppression may also occur. Hematologic toxicities are dose-related and may be more severe in renal transplant patients whose homograft is undergoing rejection. It is suggested that patients on azathioprine have complete blood counts, including platelet counts, weekly during the first month, twice monthly for the second and third months of treatment, then monthly or more frequently if dosage alterations or other therapy changes are necessary.
Delayed hematologic suppression may occur. Prompt reduction in dosage or temporary withdrawal of the drug may be necessary if there is a rapid fall in or persistently low leukocyte count, or other evidence of bone marrow depression.
Leukopenia does not correlate with therapeutic effect; therefore the dose should not be increased intentionally to lower the white blood cell count. TPMT or NUDT15 Deficiency Patients with thiopurine S-methyl transferase (TPMT) or nucleotide diphosphatase (NUDT15) deficiency may be at an increased risk of severe and life-threatening myelotoxicity if receiving conventional doses of azathioprine (see CLINICAL PHARMACOLOGY ).
Death associated with pancytopenia has been reported in patients with absent TPMT activity receiving azathioprine. In patients with severe myelosuppression, consider evaluation for TPMT and NUDT15 deficiency (see PRECAUTIONS: Laboratory Tests ).
Consider alternative therapy in patients with homozygous TPMT or NUDT15 deficiency and reduced dosages in patients with heterozygous deficiency (see DOSAGE AND ADMINISTRATION ). Serious infections Patients receiving immunosuppressants, including azathioprine, are at increased risk for bacterial, viral, fungal, protozoal, and opportunistic infections, including reactivation of latent infections.
These infections may lead to serious, including fatal outcomes. Progressive Multifocal Leukoencephalopathy Cases of JC virus-associated infection resulting in progressive multifocal leukoencephalopathy (PML), sometimes fatal, have been reported in patients treated with immunosuppressants, including azathioprine.
Risk factors for PML include treatment with immunosuppressant therapies and impairment of immune function. Consider the diagnosis of PML in any patient presenting with new-onset neurological manifestations and consider consultation with a neurologist as clinically indicated.
Consider reducing the amount of immunosuppression in patients who develop PML. In transplant patients, consider the risk that the reduced immunosuppression represents to the graft. Effect on Sperm in Animals Azathioprine has been reported to cause temporary depression in spermatogenesis and reduction in sperm viability and sperm count in mice at doses 10 times the human therapeutic dose; 1 a reduced percentage of fertile matings occurred when animals received 5 mg/kg.
2 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.
This drug should not be used for treating rheumatoid arthritis in pregnant women. 3 Azathioprine tablets are teratogenic in rabbits and mice when given in doses equivalent to the human dose (5 mg/kg daily). Abnormalities included skeletal malformations and visceral anomalies.
2 Postmarketing cases of intrahepatic cholestasis of pregnancy (ICP) have been reported in women treated with azathioprine during pregnancy. ICP symptoms and evaluated bile acid levels improved following azathioprine discontinuation.
Discontinue azathioprine tablets if ICP develops in a pregnant woman. Limited immunologic and other abnormalities have occurred in a few infants born of renal allograft recipients on azathioprine tablets. In a detailed case report, 4 documented lymphopenia, diminished IgG and IgM levels, CMV infection, and a decreased thymic shadow were noted in an infant born to a mother receiving 150 mg azathioprine and 30 mg prednisone daily throughout pregnancy.
At 10 weeks most features were normalized. 5 mg prednisone daily. 5 There have been two published reports of abnormal physical findings. Williamson and Karp described an infant born with preaxial polydactyly whose mother received azathioprine 200 mg daily and prednisone 20 mg every other day during pregnancy.
6 Tallent et al described an infant with a large myelomeningocele in the upper lumbar region, bilateral dislocated hips, and bilateral talipes equinovarus. The father was on long-term azathioprine therapy. 7 Benefit versus risk must be weighed carefully before use of azathioprine tablets in patients of reproductive potential.
There are no adequate and well-controlled studies in pregnant women. If this drug is used during pregnancy or if the patient becomes pregnant while taking this drug, the patient should be apprised of the potential hazard to the fetus.
Women of childbearing age should be advised to avoid becoming pregnant.
Spillages must be wiped immediately. Women who are pregnant, planning to be or breast-feeding should not handle Jayempi. 1. 5). 6). 4 Special warnings and precautions for use Monitoring Therapy with Jayempi in pre-existing, severe infections, in severe disorders of the liver and bone marrow function and in the presence of pancreatitis should only be initiated subject to a careful benefit/risk analysis and the precautions specified below.
Special attention should be given to monitoring the blood count. If necessary, the maintenance dose should be reduced as much as possible, provided there is clinical response. Azathioprine should only be prescribed if the patient can be adequately monitored for haematological and hepatic effects throughout the duration of therapy.
During the first 8 weeks of treatment, a complete blood count, including platelet count must be performed at least once weekly. It should be controlled more frequently: - if high doses are used - in elderly patients - if renal function is impaired.
2) - if hepatic function is impaired. 2). 8). This is particularly important in patients with severe impaired liver function and azathioprine should only be used after a careful benefit/risk analysis. Azathioprine is hepatotoxic and liver function tests should be routinely monitored during treatment.
More frequent monitoring may be advisable in those with pre-existing liver disease or receiving other potentially hepatotoxic therapy. Cases of non-cirrhotic portal hypertension/portosinusoidal vascular disease have been reported. 8).
The patients should be informed about the symptoms of liver injury and advised to contact their doctor immediately if these occur. The frequency of blood counts may be reduced after 8 weeks and be repeated monthly or at least at intervals of no longer than 3 months (maximum quarterly).
At the first sign of an abnormal change in the blood count, treatment should be discontinued immediately because the number of leucocytes and platelets may continue to decrease after the end of treatment. Patients receiving azathioprine must be advised to inform their […]