azathioprine (Rx)

Brand and Other Names:Azasan, Imuran
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Dosing & Uses

AdultPediatric

Dosage Forms & Strengths

tablet

  • 50mg
  • 75mg
  • 100mg

powder for injection

  • 100mg/vial

Kidney Transplantation

Prevention of transplant rejection

3-5 mg/kg/day IV/PO initially on day of transplant; 1 to 3 days prior to transplantation also reported (rare)  

Maintenance: 1-3 mg/kg/day IV/PO  

Rheumatoid Arthritis

1 mg/kg/day IV/PO initially in single daily dose or divided q12hr; after 6-8 weeks, increase by 0.5 mg/kg/day every 4 weeks; not to exceed 2.5 mg/kg/day  

Maintenance: Reduce daily dose by 0.5 mg/kg every 4 weeks until lowest effective dosage is reached

Lupus Nephritis (Off-label)

Induction and maintenance therapy for lupus nephritis (2012 American College of Rheumatology guidelines)

2 mg/kg/day PO with or without low-dose corticosteroids  

Crohn Disease (Off-label)

Maintenance, remission, or reduction of steroid

2-3 mg/kg PO once daily  

Ulcerative Colitis (Off-label)

Maintenance, remission, or reduction of steroid

1.5-2.5 mg/kg PO once daily  

Chronic Refractory Thrombocytopenic Purpura (Off-label)

1-2 mg/kg PO once daily to maximum daily dose of 150 mg for at least 3-6 months before typical response is observed

Dosing considerations

  • Lower dosage (100 mg/day) is reported effective in some patients
  • Longer treatment duration (up to 84 months) is reported in some patients

Dosage Forms & Strengths

tablet

  • 50mg
  • 75mg
  • 100mg

powder for injection

  • 100mg/vial

Juvenile Idiopathic Arthritis

1 mg/kg/day IV/PO initially in single daily dose or divided q12hr; may be increased by 0.5 mg/kg/day after 6-8 weeks, then by 0.5 mg/kg/day every 4 weeks; not to exceed 2.5 mg/kg/day  

Maintenance: Reduce daily dose by 0.5 mg/kg every 4 weeks until lowest effective dosage is reached

Transplantation (Off-label)

Prevention of transplant rejection

3-5 mg/kg/day IV/PO initially on day of transplant or 3 days before transplant (rare)  

Maintenance: 1-3 mg/kg/day IV/PO

Lupus Nephritis (Off-label)

Induction and maintenance therapy for lupus nephritis (2012 American College of Rheumatology guidelines)

<12 years: Safety and efficacy not established

>12 years: 2 mg/kg/day PO with or without low-dose corticosteroids

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Interactions

Interaction Checker

and azathioprine

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    No Interactions Found
    Interactions Found

    Contraindicated

      Serious - Use Alternative

        Significant - Monitor Closely

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            Contraindicated (1)

            • febuxostat

              febuxostat increases levels of azathioprine by decreasing metabolism. Contraindicated.

            Serious - Use Alternative (67)

            • adalimumab

              adalimumab and azathioprine both increase immunosuppressive effects; risk of infection. Avoid or Use Alternate Drug.

            • adenovirus types 4 and 7 live, oral

              azathioprine decreases effects of adenovirus types 4 and 7 live, oral by pharmacodynamic antagonism. Avoid or Use Alternate Drug. Immunosuppressives may diminish therapeutic effects of vaccines and increase risk of adverse effects (increased risk of infection). Live-attenuated vaccines should be avoided for at least 3mo after cessation of immunosuppressive therapy.

            • alefacept

              alefacept and azathioprine both increase immunosuppressive effects; risk of infection. Avoid or Use Alternate Drug.

            • allopurinol

              allopurinol increases levels of azathioprine by decreasing metabolism. Avoid or Use Alternate Drug. Increased risk of bone marrow toxicity.

            • anakinra

              anakinra and azathioprine both increase immunosuppressive effects; risk of infection. Avoid or Use Alternate Drug.

            • anthrax vaccine

              azathioprine decreases effects of anthrax vaccine by pharmacodynamic antagonism. Contraindicated. Immunosuppressants also increase risk of infection with concomitant live vaccines.

            • antithymocyte globulin equine

              antithymocyte globulin equine and azathioprine both increase immunosuppressive effects; risk of infection. Avoid or Use Alternate Drug.

            • antithymocyte globulin rabbit

              antithymocyte globulin rabbit and azathioprine both increase immunosuppressive effects; risk of infection. Avoid or Use Alternate Drug.

            • baricitinib

              baricitinib, azathioprine. Either increases toxicity of the other by immunosuppressive effects; risk of infection. Avoid or Use Alternate Drug. Baricitinib is not recommended in combination with other JAK inhibitors, biologic DMARDs, or potent immunosuppressives.

            • basiliximab

              azathioprine and basiliximab both increase immunosuppressive effects; risk of infection. Avoid or Use Alternate Drug.

            • BCG vaccine live

              azathioprine decreases effects of BCG vaccine live by pharmacodynamic antagonism. Contraindicated. Immunosuppressants also increase risk of infection with concomitant live vaccines.

            • canakinumab

              azathioprine and canakinumab both increase immunosuppressive effects; risk of infection. Avoid or Use Alternate Drug.

            • diphtheria & tetanus toxoids

              azathioprine decreases effects of diphtheria & tetanus toxoids by pharmacodynamic antagonism. Contraindicated. Immunosuppressants also increase risk of infection with concomitant live vaccines.

            • diphtheria & tetanus toxoids/ acellular pertussis vaccine

              azathioprine decreases effects of diphtheria & tetanus toxoids/ acellular pertussis vaccine by pharmacodynamic antagonism. Contraindicated. Immunosuppressants also increase risk of infection with concomitant live vaccines.

            • diphtheria & tetanus toxoids/acellular pertussis/poliovirus, inactivated vaccine

              azathioprine decreases effects of diphtheria & tetanus toxoids/acellular pertussis/poliovirus, inactivated vaccine by pharmacodynamic antagonism. Contraindicated. Immunosuppressants also increase risk of infection with concomitant live vaccines.

            • etanercept

              azathioprine and etanercept both increase immunosuppressive effects; risk of infection. Avoid or Use Alternate Drug.

            • everolimus

              azathioprine and everolimus both increase immunosuppressive effects; risk of infection. Avoid or Use Alternate Drug.

            • glatiramer

              azathioprine and glatiramer both increase immunosuppressive effects; risk of infection. Avoid or Use Alternate Drug.

            • golimumab

              azathioprine and golimumab both increase immunosuppressive effects; risk of infection. Avoid or Use Alternate Drug.

            • hepatitis A vaccine inactivated

              azathioprine decreases effects of hepatitis A vaccine inactivated by pharmacodynamic antagonism. Contraindicated. Immunosuppressants also increase risk of infection with concomitant live vaccines.

            • hepatitis a/b vaccine

              azathioprine decreases effects of hepatitis a/b vaccine by pharmacodynamic antagonism. Contraindicated. Immunosuppressants also increase risk of infection with concomitant live vaccines.

            • hepatitis a/typhoid vaccine

              azathioprine decreases effects of hepatitis a/typhoid vaccine by pharmacodynamic antagonism. Contraindicated. Immunosuppressants also increase risk of infection with concomitant live vaccines.

            • hepatitis b vaccine

              azathioprine decreases effects of hepatitis b vaccine by pharmacodynamic antagonism. Contraindicated. Immunosuppressants also increase risk of infection with concomitant live vaccines.

            • human papillomavirus vaccine, nonavalent

              azathioprine decreases effects of human papillomavirus vaccine, nonavalent by pharmacodynamic antagonism. Avoid or Use Alternate Drug. Immunosuppressive therapies, including irradiation, antimetabolites, alkylating agents, cytotoxic drugs, and corticosteroids (used in greater than physiologic doses), may reduce the immune responses to vaccines.

            • human papillomavirus vaccine, quadrivalent

              azathioprine decreases effects of human papillomavirus vaccine, quadrivalent by pharmacodynamic antagonism. Avoid or Use Alternate Drug. Immunosuppressive therapies, including irradiation, antimetabolites, alkylating agents, cytotoxic drugs, and corticosteroids (used in greater than physiologic doses), may reduce the immune responses to vaccines.

            • hydroxychloroquine sulfate

              azathioprine and hydroxychloroquine sulfate both increase immunosuppressive effects; risk of infection. Avoid or Use Alternate Drug.

            • infliximab

              azathioprine and infliximab both increase immunosuppressive effects; risk of infection. Avoid or Use Alternate Drug.

            • influenza virus vaccine quadrivalent

              azathioprine decreases effects of influenza virus vaccine quadrivalent by pharmacodynamic antagonism. Contraindicated. Immunosuppressants also increase risk of infection with concomitant live vaccines.

            • influenza virus vaccine quadrivalent, adjuvanted

              azathioprine decreases effects of influenza virus vaccine quadrivalent, adjuvanted by pharmacodynamic antagonism. Avoid or Use Alternate Drug. Immunosuppressive drugs may reduce the immune response to influenza vaccine.

            • influenza virus vaccine quadrivalent, cell-cultured

              azathioprine decreases effects of influenza virus vaccine quadrivalent, cell-cultured by pharmacodynamic antagonism. Contraindicated. Immunosuppressants also increase risk of infection with concomitant live vaccines.

            • influenza virus vaccine quadrivalent, intranasal

              azathioprine decreases effects of influenza virus vaccine quadrivalent, intranasal by pharmacodynamic antagonism. Contraindicated. Immunosuppressants also increase risk of infection with concomitant live vaccines.

            • influenza virus vaccine trivalent

              azathioprine decreases effects of influenza virus vaccine trivalent by pharmacodynamic antagonism. Contraindicated. Immunosuppressants also increase risk of infection with concomitant live vaccines.

            • influenza virus vaccine trivalent, adjuvanted

              azathioprine decreases effects of influenza virus vaccine trivalent, adjuvanted by pharmacodynamic antagonism. Avoid or Use Alternate Drug. Immunosuppressive drugs may reduce the immune response to influenza vaccine.

            • Japanese encephalitis virus vaccine

              azathioprine decreases effects of Japanese encephalitis virus vaccine by pharmacodynamic antagonism. Contraindicated. Immunosuppressants also increase risk of infection with concomitant live vaccines.

            • leflunomide

              azathioprine and leflunomide both increase immunosuppressive effects; risk of infection. Avoid or Use Alternate Drug.

            • measles (rubeola) vaccine

              azathioprine decreases effects of measles (rubeola) vaccine by pharmacodynamic antagonism. Contraindicated. Immunosuppressants also increase risk of infection with concomitant live vaccines.

            • measles mumps and rubella vaccine, live

              azathioprine decreases effects of measles mumps and rubella vaccine, live by pharmacodynamic antagonism. Contraindicated. Immunosuppressants also increase risk of infection with concomitant live vaccines.

            • measles, mumps, rubella and varicella vaccine, live

              azathioprine decreases effects of measles, mumps, rubella and varicella vaccine, live by pharmacodynamic antagonism. Contraindicated. Immunosuppressants also increase risk of infection with concomitant live vaccines.

            • meningococcal A C Y and W-135 polysaccharide vaccine combined

              azathioprine decreases effects of meningococcal A C Y and W-135 polysaccharide vaccine combined by pharmacodynamic antagonism. Contraindicated. Immunosuppressants also increase risk of infection with concomitant live vaccines.

            • muromonab CD3

              azathioprine and muromonab CD3 both increase immunosuppressive effects; risk of infection. Avoid or Use Alternate Drug.

            • mycophenolate

              azathioprine and mycophenolate both increase immunosuppressive effects; risk of infection. Avoid or Use Alternate Drug.

            • pexidartinib

              azathioprine and pexidartinib both increase Other (see comment). Avoid or Use Alternate Drug. Pexidartinib can cause hepatotoxicity. Avoid coadministration of pexidartinib with other products know to cause hepatoxicity.

            • pneumococcal vaccine 13-valent

              azathioprine decreases effects of pneumococcal vaccine 13-valent by pharmacodynamic antagonism. Contraindicated. Immunosuppressants also increase risk of infection with concomitant live vaccines.

            • pneumococcal vaccine heptavalent

              azathioprine decreases effects of pneumococcal vaccine heptavalent by pharmacodynamic antagonism. Contraindicated. Immunosuppressants also increase risk of infection with concomitant live vaccines.

            • pneumococcal vaccine polyvalent

              azathioprine decreases effects of pneumococcal vaccine polyvalent by pharmacodynamic antagonism. Contraindicated. Immunosuppressants also increase risk of infection with concomitant live vaccines.

            • pretomanid

              azathioprine, pretomanid. Either increases toxicity of the other by Other (see comment). Avoid or Use Alternate Drug. Comment: Pretomanid regimen associated with hepatotoxicity. Avoid alcohol and hepatotoxic agents, including herbal supplements and drugs other than bedaquiline and linezolid.

            • rabies vaccine

              azathioprine decreases effects of rabies vaccine by pharmacodynamic antagonism. Contraindicated. Immunosuppressants may interfere with development of active immunity.

            • rabies vaccine chick embryo cell derived

              azathioprine decreases effects of rabies vaccine chick embryo cell derived by pharmacodynamic antagonism. Contraindicated. Immunosuppressants also increase risk of infection with concomitant live vaccines.

            • rilonacept

              azathioprine and rilonacept both increase immunosuppressive effects; risk of infection. Avoid or Use Alternate Drug.

            • rotavirus oral vaccine, live

              azathioprine decreases effects of rotavirus oral vaccine, live by pharmacodynamic antagonism. Contraindicated. Immunosuppressants also increase risk of infection with concomitant live vaccines.

            • rubella vaccine

              azathioprine decreases effects of rubella vaccine by pharmacodynamic antagonism. Contraindicated. Immunosuppressants also increase risk of infection with concomitant live vaccines.

            • sirolimus

              azathioprine and sirolimus both increase immunosuppressive effects; risk of infection. Avoid or Use Alternate Drug.

            • smallpox (vaccinia) vaccine, live

              azathioprine decreases effects of smallpox (vaccinia) vaccine, live by pharmacodynamic antagonism. Contraindicated. Immunosuppressants also increase risk of infection with concomitant live vaccines.

            • tacrolimus

              azathioprine and tacrolimus both increase immunosuppressive effects; risk of infection. Avoid or Use Alternate Drug.

            • temsirolimus

              azathioprine and temsirolimus both increase immunosuppressive effects; risk of infection. Avoid or Use Alternate Drug.

            • tetanus toxoid adsorbed or fluid

              azathioprine decreases effects of tetanus toxoid adsorbed or fluid by pharmacodynamic antagonism. Contraindicated. Immunosuppressants also increase risk of infection with concomitant live vaccines.

            • tick-borne encephalitis vaccine

              azathioprine decreases effects of tick-borne encephalitis vaccine by pharmacodynamic antagonism. Contraindicated. Immunosuppressants also increase risk of infection with concomitant live vaccines.

            • tocilizumab

              tocilizumab and azathioprine both increase immunosuppressive effects; risk of infection. Avoid or Use Alternate Drug.

            • tofacitinib

              azathioprine, tofacitinib. Either increases toxicity of the other by immunosuppressive effects; risk of infection. Avoid or Use Alternate Drug.

            • tongkat ali

              azathioprine and tongkat ali both increase immunosuppressive effects; risk of infection. Avoid or Use Alternate Drug.

            • travelers diarrhea and cholera vaccine inactivated

              azathioprine decreases effects of travelers diarrhea and cholera vaccine inactivated by pharmacodynamic antagonism. Contraindicated. Immunosuppressants also increase risk of infection with concomitant live vaccines.

            • typhoid polysaccharide vaccine

              azathioprine decreases effects of typhoid polysaccharide vaccine by pharmacodynamic antagonism. Contraindicated. Immunosuppressants also increase risk of infection with concomitant live vaccines.

            • typhoid vaccine live

              azathioprine decreases effects of typhoid vaccine live by pharmacodynamic antagonism. Contraindicated. Immunosuppressants also increase risk of infection with concomitant live vaccines.

            • ustekinumab

              azathioprine and ustekinumab both increase immunosuppressive effects; risk of infection. Avoid or Use Alternate Drug.

            • varicella virus vaccine live

              azathioprine decreases effects of varicella virus vaccine live by pharmacodynamic antagonism. Contraindicated. Immunosuppressants also increase risk of infection with concomitant live vaccines.

            • yellow fever vaccine

              azathioprine decreases effects of yellow fever vaccine by pharmacodynamic antagonism. Contraindicated. Immunosuppressants also increase risk of infection with concomitant live vaccines.

            • zoster vaccine live

              azathioprine decreases effects of zoster vaccine live by pharmacodynamic antagonism. Contraindicated. Immunosuppressants also increase risk of infection with concomitant live vaccines.

            Monitor Closely (54)

            • antithrombin alfa

              azathioprine decreases effects of antithrombin alfa by unknown mechanism. Use Caution/Monitor.

            • antithrombin III

              azathioprine decreases effects of antithrombin III by unknown mechanism. Use Caution/Monitor.

            • argatroban

              azathioprine decreases effects of argatroban by unknown mechanism. Use Caution/Monitor.

            • astragalus

              azathioprine increases and astragalus decreases immunosuppressive effects; risk of infection. Effect of interaction is not clear, use caution. Use Caution/Monitor.

            • belatacept

              belatacept and azathioprine both increase immunosuppressive effects; risk of infection. Use Caution/Monitor.

            • bemiparin

              azathioprine decreases effects of bemiparin by unknown mechanism. Use Caution/Monitor.

            • benazepril

              benazepril, azathioprine. Mechanism: pharmacodynamic synergism. Use Caution/Monitor. Risk of neutropenia.

            • bivalirudin

              azathioprine decreases effects of bivalirudin by unknown mechanism. Use Caution/Monitor.

            • captopril

              captopril, azathioprine. Mechanism: pharmacodynamic synergism. Use Caution/Monitor. Risk of neutropenia.

            • cholera vaccine

              azathioprine decreases effects of cholera vaccine by immunosuppressive effects; risk of infection. Modify Therapy/Monitor Closely. Immunosuppressive therapies, including irradiation, antimetabolites, alkylating agents, cytotoxic drugs and corticosteroids (used in greater than physiologic doses), may reduce the immune response to cholera vaccine.

            • dalteparin

              azathioprine decreases effects of dalteparin by unknown mechanism. Use Caution/Monitor.

            • dengue vaccine

              azathioprine decreases effects of dengue vaccine by immunosuppressive effects; risk of infection. Use Caution/Monitor. Immunosuppressive therapies (eg, irradiation, antimetabolites, alkylating agents, cytotoxic drugs, corticosteroids [greater than physiologic doses]) may reduce immune response to dengue vaccine.

            • denosumab

              azathioprine, denosumab. Other (see comment). Use Caution/Monitor. Comment: Caution should be taken in patients on concomitant immunosuppressants or with impaired immune systems because of increased risk for serious infections.

            • echinacea

              azathioprine increases and echinacea decreases immunosuppressive effects; risk of infection. Effect of interaction is not clear, use caution. Use Caution/Monitor.

            • enalapril

              enalapril, azathioprine. Mechanism: pharmacodynamic synergism. Use Caution/Monitor. Risk of neutropenia.

            • enoxaparin

              azathioprine decreases effects of enoxaparin by unknown mechanism. Use Caution/Monitor.

            • fingolimod

              azathioprine increases effects of fingolimod by immunosuppressive effects; risk of infection. Modify Therapy/Monitor Closely. Concomitant therapy is expected to increase the risk of immunosuppression. Use caution when switching patients from long-acting therapies with immune effects. .

            • fondaparinux

              azathioprine decreases effects of fondaparinux by unknown mechanism. Use Caution/Monitor.

            • fosinopril

              fosinopril, azathioprine. Mechanism: pharmacodynamic synergism. Use Caution/Monitor. Risk of neutropenia.

            • haemophilus influenzae type b vaccine

              azathioprine decreases effects of haemophilus influenzae type b vaccine by pharmacodynamic antagonism. Modify Therapy/Monitor Closely. Avoid vaccination during chemotherapy or radiation therapy if possible because antibody response might be suboptimal. Patients vaccinated within a 14-day period before starting or during immunosuppressive therapy should be revaccinated =3 months after therapy is discontinued if immune competence has been restored.

            • heparin

              azathioprine decreases effects of heparin by unknown mechanism. Use Caution/Monitor.

            • hydroxyurea

              azathioprine, hydroxyurea. Other (see comment). Use Caution/Monitor. Comment: Combination may increase risk of myelosuppression.

            • ifosfamide

              ifosfamide, azathioprine. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Coadministration with ifosfamide may increase the risk of immunosuppression and myelosuppression.

            • imidapril

              imidapril, azathioprine. Mechanism: pharmacodynamic synergism. Use Caution/Monitor. Risk of neutropenia.

            • influenza virus vaccine quadrivalent, recombinant

              azathioprine decreases effects of influenza virus vaccine quadrivalent, recombinant by pharmacodynamic antagonism. Use Caution/Monitor. Immune response to vaccine may be decreased in immunocompromised individuals.

            • influenza virus vaccine trivalent, recombinant

              azathioprine decreases effects of influenza virus vaccine trivalent, recombinant by pharmacodynamic antagonism. Use Caution/Monitor. Immune response to vaccine may be decreased in immunocompromised individuals.

            • isavuconazonium sulfate

              azathioprine and isavuconazonium sulfate both decrease immunosuppressive effects; risk of infection. Use Caution/Monitor.

            • lisinopril

              lisinopril, azathioprine. Mechanism: pharmacodynamic synergism. Use Caution/Monitor. Risk of neutropenia.

            • lomustine

              lomustine and azathioprine both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution should be taken in patients on concomitant immunosuppressants or with impaired immune systems because of increased risk for serious infections.

            • maitake

              azathioprine increases and maitake decreases immunosuppressive effects; risk of infection. Effect of interaction is not clear, use caution. Use Caution/Monitor.

            • meningococcal group B vaccine

              azathioprine decreases effects of meningococcal group B vaccine by pharmacodynamic antagonism. Use Caution/Monitor. Individuals with altered immunocompetence may have reduced immune responses to the vaccine.

            • mercaptopurine

              azathioprine and mercaptopurine both increase immunosuppressive effects; risk of infection. Use Caution/Monitor.

            • mesalamine

              mesalamine increases toxicity of azathioprine by Mechanism: unspecified interaction mechanism. Use Caution/Monitor. Increased risk for blood disorders.

            • mipomersen

              mipomersen, azathioprine. Either increases toxicity of the other by Other (see comment). Use Caution/Monitor. Comment: Both drugs have potential to increase hepatic enzymes; monitor LFTs.

            • moexipril

              moexipril, azathioprine. Mechanism: pharmacodynamic synergism. Use Caution/Monitor. Risk of neutropenia.

            • ocrelizumab

              azathioprine and ocrelizumab both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Coadministration of ocrelizumab with immunosuppessants is expected to increase the risk of immunosuppression.

            • olaparib

              azathioprine and olaparib both increase pharmacodynamic synergism. Use Caution/Monitor. Coadministration with other other myelosuppressive anticancer agents, including DNA damaging agents, may potentiate and prolongate the myelosuppressive toxicity.

            • oxaliplatin

              oxaliplatin and azathioprine both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Use of oxaliplatin with concomitant immunosuppressants or with impaired immune systems may increased risk for serious infections.

            • ozanimod

              ozanimod, azathioprine. Either increases effects of the other by immunosuppressive effects; risk of infection. Use Caution/Monitor. Coadministration with immunosuppressive therapies may increase the risk of additive immune effects during therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs in order to avoid unintended additive immunosuppressive effects.

            • perindopril

              perindopril, azathioprine. Mechanism: pharmacodynamic synergism. Use Caution/Monitor. Risk of neutropenia.

            • phenindione

              azathioprine decreases effects of phenindione by unknown mechanism. Use Caution/Monitor.

            • poliovirus vaccine inactivated

              azathioprine decreases effects of poliovirus vaccine inactivated by pharmacodynamic antagonism. Modify Therapy/Monitor Closely. Avoid vaccination during chemotherapy or radiation therapy if possible because antibody response might be suboptimal. Patients vaccinated within a 14-day period before starting or during immunosuppressive therapy should be revaccinated =3 months after therapy is discontinued if immune competence has been restored. .

            • ponesimod

              ponesimod and azathioprine both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

            • protamine

              azathioprine decreases effects of protamine by unknown mechanism. Use Caution/Monitor.

            • quinapril

              quinapril, azathioprine. Mechanism: pharmacodynamic synergism. Use Caution/Monitor. Risk of neutropenia.

            • ramipril

              ramipril, azathioprine. Mechanism: pharmacodynamic synergism. Use Caution/Monitor. Risk of neutropenia.

            • siponimod

              siponimod and azathioprine both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

            • sipuleucel-T

              azathioprine decreases effects of sipuleucel-T by pharmacodynamic antagonism. Modify Therapy/Monitor Closely.

            • trandolapril

              trandolapril, azathioprine. Mechanism: pharmacodynamic synergism. Use Caution/Monitor. Risk of neutropenia.

            • trastuzumab

              trastuzumab, azathioprine. Either increases toxicity of the other by immunosuppressive effects; risk of infection. Use Caution/Monitor. Neutropenia or febrile neutropenia incidence were increased when trastuzumab was coadministered with myelosuppressive chemotherapy. .

            • trastuzumab deruxtecan

              trastuzumab deruxtecan, azathioprine. Either increases toxicity of the other by immunosuppressive effects; risk of infection. Use Caution/Monitor. Neutropenia or febrile neutropenia incidence were increased when trastuzumab was coadministered with myelosuppressive chemotherapy. .

            • warfarin

              azathioprine decreases effects of warfarin by unknown mechanism. Use Caution/Monitor.

            • zidovudine

              azathioprine, zidovudine. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Increased risk of myelosuppression.

            • zoster vaccine recombinant

              azathioprine decreases effects of zoster vaccine recombinant by pharmacodynamic antagonism. Use Caution/Monitor. Immunosuppressive therapies may reduce the effectiveness of zoster vaccine recombinant.

            Minor (1)

            • sulfamethoxazole

              sulfamethoxazole, azathioprine. Mechanism: pharmacodynamic synergism. Minor/Significance Unknown. Leukopenia due to additive myelosuppression.

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            Adverse Effects

            >10%

            Leukopenia (28-50%)

            Infection (20%)

            <1%

            Lymphoma

            Frequency Not Defined

            Abdominal pain

            Alopecia

            Arthralgia

            Bacterial, fungal, protozoal, viral infections

            Bone marrow suppression

            Diarrhea

            Fever

            Hepatotoxicity

            Macrocytic anemia

            Myalgia

            Nausea or vomiting

            Rash

            Skin cancer

            Steatorrhea

            Sweet syndrome (acute febrile neutrophilic dermatosis)

            Thrombocytopenia

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            Warnings

            Black Box Warnings

            Chronic immunosuppression with this purine antimetabolite increases neoplasia risk, mutagenic risk, and hematologic toxicities

            Reported malignancies include posttransplant lymphoma and hepatosplenic T-cell lymphoma (HSTCL) in patients with inflammatory bowel disease

            Prescribing physicians should be familiar with mutagenic potential and with possible hematologic toxicities

            Contraindications

            Documented hypersensitivity

            Pregnancy, lactation

            Rheumatoid arthritis: Patients previously treated with alkylating agents

            Cautions

            Long-term use increases risk of neoplasia

            Increased risk of infection and hepatotoxicity; monitor liver function periodically; hepatic sinudoidal obstruction syndrome reported; discontinue therapy if suspected

            Cases of JC virus-associated infection resulting in progressive multifocal leukoencephalopathy (PML), sometimes fatal, reported in patients treated with immunosuppressants, including azathioprine

            Severe leukopenia, thrombocytopenia, anemias including macrocytic anemia, and/or pancytopenia may occur; severe bone marrow suppression may also occur; patients with or nucleotide diphosphatase (NUDT15) deficiency may be at an increased risk of myelotoxicity if patient receiving conventional doses of drug; delayed hematologic suppression may occur; prompt reduction in dosage or temporary withdrawal of drug may be necessary if there is rapid fall in or persistently low leukocyte count, or other evidence of bone marrow depression; leukopenia does not correlate with therapeutic effect; therefore dose should not be increased intentionally to lower white blood cell count

            In patients with severe myelosuppression, consider evaluation for TPMT and NUDT15 deficiency; consider alternative therapy in patients with homozygous TPMT or NUDT15 deficiency and reduced dosages in patients with heterozygous deficiency

            Patients receiving immunosuppressants, 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

            Frequency of gastrointestinal adverse effects (nausea and vomiting) may decrease with dividing dose or administering after meals

            Hepatosplenic T-cell lymphoma

            • Rare postmarketing cases of HSTCL reported primarily in adolescent and young adult patients with Crohn disease and ulcerative colitis treated with tumor necrosis factor (TNF) blockers
            • Reports have also included 1 patient being treated for psoriasis and 2 patients being treated for rheumatoid arthritis
            • HSTCL is an aggressive, rare type of T-cell lymphoma that is usually fatal
            • Most reported cases with TNF blockers have occurred in context of concomitant treatment with azathioprine or 6-mercaptopurine (6-MP), though cases have been reported with azathioprine or 6-MP alone
            • In the FDA Adverse Event Reporting System (AERS) database, the literature, and the HSTCL Cancer Survivors' Network, HSTCL cases have been identified in association with the following drugs: infliximab (20), etanercept (1), adalimumab (2), infliximab/adalimumab (5), certolizumab (0), golimumab (0), azathioprine (12), 6-MP (3)
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            Pregnancy & Lactation

            Pregnancy category: D

            Lactation: Drug excreted at low levels in breast milk; use not recommended

            Pregnancy Categories

            A: Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.

            B: May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk.

            C: Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done.

            D: Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk.

            X: Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist.

            NA: Information not available.

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            Pharmacology

            Mechanism of Action

            Purine antimetabolite, converted to 6-MP; may inhibit synthesis of DNA, RNA, and proteins; interferes with cellular metabolism; may inhibit mitosis

            Absorption

            Well absorbed orally

            Duration: Variable (crosses placenta)

            Peak plasma time: PO, 1-2 hr

            Peak plasma concentration: <1 mcg/mL

            Distribution

            Protein bound: 30%

            Metabolism

            Metabolized in liver

            Metabolites: 6-MP, 6-thiouric acid

            Elimination

            Half-life: Parent drug, 12 min; 6-MP, 0.7-3 hr; slightly prolonged in end-stage renal disease

            Dialyzable: Partially

            Excretion: Urine (primarily as metabolites)

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            Administration

            Oral suspension of 50 mg/mL requires extemporaneous compounding by pharmacist

            IV Incompatibilities

            Stable in neutral or acid solutions; in alkaline solutions, hydrolyzed to 6-MP

            IV Administration

            Can be administered by IV push over 5 minutes at concentration not exceeding 10 mg/mL

            Can be further diluted with NS or D5W and administered by intermittent infusion over 30-60 minutes (usual approach); however, infusions over periods ranging from 5 minutes to 8 hours have been done

            Storage

            Store powder at room temperature (25°C); reconstituted solution is stable for 2 weeks at room temperature but may be less stable under refrigeration

            Protect from light

            Because there are no preservatives, drug must be used within 24 hours

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            Images

            BRAND FORM. UNIT PRICE PILL IMAGE
            azathioprine oral
            -
            50 mg tablet
            azathioprine oral
            -
            50 mg tablet
            azathioprine oral
            -
            50 mg tablet
            azathioprine oral
            -
            50 mg tablet
            Imuran oral
            -
            50 mg tablet
            Azasan oral
            -
            100 mg tablet
            Azasan oral
            -
            75 mg tablet

            Copyright © 2010 First DataBank, Inc.

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            Patient Handout

            Patient Education
            azathioprine oral

            AZATHIOPRINE - ORAL

            (AY-za-THYE-oh-preen)

            COMMON BRAND NAME(S): Imuran

            WARNING: Azathioprine may rarely increase your risk of developing certain types of cancer (such as lymphoma, skin cancer). This risk is higher in people using azathioprine after an organ transplant and in children/young adults being treated for certain bowel diseases (such as Crohn's disease, ulcerative colitis). Keep all medical and lab appointments. Tell your doctor right away if you develop any of the following symptoms: unusual skin changes, change in the appearance/size of moles, unusual growths/lumps, swollen lymph nodes, swollen abdomen, unexplained weight loss, night sweats.This medication may decrease bone marrow function, an effect that may lead to a low number of blood cells such as red cells, white cells, and platelets. This effect can cause anemia, decrease your body's ability to fight an infection, or cause easy bruising/bleeding. Tell your doctor right away if you develop any of the following symptoms: unusual tiredness, pale skin, signs of infection (such as sore throat that doesn't go away, fever, chills), easy bruising/bleeding.

            USES: Azathioprine is used to prevent organ rejection in people who have received a kidney transplant. It is usually taken along with other medications to allow your new kidney to function normally. Azathioprine is also used to treat rheumatoid arthritis. In this condition, the body's defense system (immune system) attacks healthy joints. Azathioprine belongs to a class of drugs known as immunosuppressants. It works by weakening the immune system to help your body accept the new kidney as if it were your own (in the case of an organ transplant) or to prevent further damage to your joints (in the case of rheumatoid arthritis).Talk to your doctor about the risks and benefits of azathioprine, especially when used by children and young adults.

            HOW TO USE: Take this medication by mouth as directed by your doctor, usually once or twice daily. Take this medication with food to reduce stomach upset.The dosage is based on your medical condition, weight, and response to treatment. Do not increase your dose or use this drug more often or for longer than prescribed. Your condition will not improve any faster, and your risk of serious side effects will increase.Use this medication regularly to get the most benefit from it. To help you remember, take it at the same time(s) each day.For the treatment of arthritis, it may take up to 2 months before your symptoms get better. Tell your doctor if your condition does not get better after 3 months of treatment.Since this drug can be absorbed through the skin and lungs and may harm an unborn baby, women who are pregnant or who may become pregnant should not handle this medication or breathe the dust from the tablets.

            SIDE EFFECTS: See also Warning section.Nausea or vomiting may occur. Taking this medication after meals may help lessen these effects. Temporary hair loss may also occur. If any of these effects last or get worse, tell your doctor or pharmacist promptly.People using this medication may have serious side effects. However, you have been prescribed this drug because your doctor has judged that the benefit to you is greater than the risk of side effects. Careful monitoring by your doctor may decrease your risk.Tell your doctor right away if you have any serious side effects, including: diarrhea, new or worsening joint/muscle pain.Get medical help right away if you have any very serious side effects, including: symptoms of liver disease (such as nausea/vomiting that doesn't stop, stomach/abdominal pain, dark urine, yellowing eyes/skin).This medication may increase your risk of getting a rare but very serious (possibly fatal) brain infection (progressive multifocal leukoencephalopathy-PML). Get medical help right away if you have any of these side effects: clumsiness, loss of coordination/balance, weakness, sudden change in your thinking (such as confusion, difficulty concentrating, memory loss), difficulty talking/walking, seizure, vision changes.A very serious allergic reaction to this drug is rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction, including: rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing.This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.In the US -Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088 or at www.fda.gov/medwatch.In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.

            PRECAUTIONS: Before taking azathioprine, tell your doctor or pharmacist if you are allergic to it, or to mercaptopurine; or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.Before using this medication, tell your doctor or pharmacist your medical history, especially of: kidney disease, liver disease, cancer, certain enzyme disorders (TPMT deficiency, NUDT15 deficiency).This medication may increase your risk of developing skin cancer. Limit your time in the sun. Avoid tanning booths and sunlamps. Use sunscreen and wear protective clothing when outdoors. Your doctor may direct you to avoid phototherapy while you use this product. Ask your doctor for details.Azathioprine can make you more likely to get infections or may worsen any current infections. Avoid contact with people who have infections that may spread to others (such as chickenpox, measles, flu). Consult your doctor if you have been exposed to an infection or for more details.Before having surgery, tell your doctor or dentist about all the products you use (including prescription drugs, nonprescription drugs, and herbal products).Do not have immunizations/vaccinations without the consent of your doctor. Avoid contact with people who have recently received live vaccines (such as flu vaccine inhaled through the nose).To lower the chance of getting cut, bruised, or injured, use caution with sharp objects like razors and nail cutters, and avoid activities such as contact sports.Since this drug can be absorbed through the skin and lungs and may harm an unborn baby, women who are pregnant or who may become pregnant should not handle this medication or breathe the dust from the tablets.Tell your doctor if you are pregnant or plan to become pregnant. You should not become pregnant while using azathioprine. Azathioprine may harm an unborn baby. Ask about reliable forms of birth control while using this medication. If you become pregnant, talk to your doctor right away about the risks and benefits of this medication.This medication passes into breast milk and may have undesirable effects on a nursing infant. Consult your doctor before breast-feeding.

            DRUG INTERACTIONS: Drug interactions may change how your medications work or increase your risk for serious side effects. This document does not contain all possible drug interactions. Keep a list of all the products you use (including prescription/nonprescription drugs and herbal products) and share it with your doctor and pharmacist. Do not start, stop, or change the dosage of any medicines without your doctor's approval.Some products that may interact with this drug are: febuxostat, past or present use of certain cancer drugs (such as cyclophosphamide, melphalan), other drugs that weaken the immune system/increase the risk of infection (such as rituximab, tofacitinib).Azathioprine is very similar to mercaptopurine. Do not use medications containing mercaptopurine while using azathioprine.

            OVERDOSE: If someone has overdosed and has serious symptoms such as passing out or trouble breathing, call 911. Otherwise, call a poison control center right away. US residents can call their local poison control center at 1-800-222-1222. Canada residents can call a provincial poison control center.

            NOTES: Do not share this medication with others.Lab and/or medical tests (such as complete blood count, liver/kidney function) should be done while you are taking this medication. Keep all medical and lab appointments. Consult your doctor for more details.If you have had an organ transplant, attend a transplant education class or support group. Learn the symptoms of organ rejection such as a feeling of being ill, fever, pain around the transplanted organ, and the signs of a failing transplanted organ (a decrease in the amount of urine with kidney transplant). Get medical help right away if these symptoms occur.

            MISSED DOSE: If you miss a dose, take it as soon as you remember. If it is near the time of the next dose, skip the missed dose. Take your next dose at the regular time. Do not double the dose to catch up.

            STORAGE: Store at room temperature away from light and moisture. Do not store in the bathroom. Keep all medications away from children and pets.Do not flush medications down the toilet or pour them into a drain unless instructed to do so. Properly discard this product when it is expired or no longer needed. Consult your pharmacist or local waste disposal company.

            MEDICAL ALERT: Your condition can cause complications in a medical emergency. For information about enrolling in MedicAlert, call 1-888-633-4298 (US) or 1-800-668-1507 (Canada).

            Information last revised August 2021. Copyright(c) 2021 First Databank, Inc.

            IMPORTANT: HOW TO USE THIS INFORMATION: This is a summary and does NOT have all possible information about this product. This information does not assure that this product is safe, effective, or appropriate for you. This information is not individual medical advice and does not substitute for the advice of your health care professional. Always ask your health care professional for complete information about this product and your specific health needs.

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            Formulary

            FormularyPatient Discounts

            Adding plans allows you to compare formulary status to other drugs in the same class.

            To view formulary information first create a list of plans. Your list will be saved and can be edited at any time.

            Adding plans allows you to:

            • View the formulary and any restrictions for each plan.
            • Manage and view all your plans together – even plans in different states.
            • Compare formulary status to other drugs in the same class.
            • Access your plan list on any device – mobile or desktop.

            The above information is provided for general informational and educational purposes only. Individual plans may vary and formulary information changes. Contact the applicable plan provider for the most current information.

            Tier Description
            1 This drug is available at the lowest co-pay. Most commonly, these are generic drugs.
            2 This drug is available at a middle level co-pay. Most commonly, these are "preferred" (on formulary) brand drugs.
            3 This drug is available at a higher level co-pay. Most commonly, these are "non-preferred" brand drugs.
            4 This drug is available at a higher level co-pay. Most commonly, these are "non-preferred" brand drugs or specialty prescription products.
            5 This drug is available at a higher level co-pay. Most commonly, these are "non-preferred" brand drugs or specialty prescription products.
            6 This drug is available at a higher level co-pay. Most commonly, these are "non-preferred" brand drugs or specialty prescription products.
            NC NOT COVERED – Drugs that are not covered by the plan.
            Code Definition
            PA Prior Authorization
            Drugs that require prior authorization. This restriction requires that specific clinical criteria be met prior to the approval of the prescription.
            QL Quantity Limits
            Drugs that have quantity limits associated with each prescription. This restriction typically limits the quantity of the drug that will be covered.
            ST Step Therapy
            Drugs that have step therapy associated with each prescription. This restriction typically requires that certain criteria be met prior to approval for the prescription.
            OR Other Restrictions
            Drugs that have restrictions other than prior authorization, quantity limits, and step therapy associated with each prescription.
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            Medscape prescription drug monographs are based on FDA-approved labeling information, unless otherwise noted, combined with additional data derived from primary medical literature.