Imuran 50 mg (Azathioprine 50mg)

What is azathioprine?

Azathioprine lowers your body's immune system. The immune system helps your body fight infections. The immune system can also fight or "reject" a transplanted organ such as a liver or kidney. This is because the immune system treats the new organ as an invader. Azathioprine is used to prevent your body from rejecting a transplanted kidney. It is also used to treat symptoms of rheumatoid arthritis. Azathioprine may also be used for purposes not listed in this medication guide.

What is the most important information I should know about azathioprine?

Some people using azathioprine have developed a rare fast-growing type of lymphoma (cancer). This condition affects the liver, spleen, and bone marrow, and it can be fatal. This has occurred mainly in teenagers and young adults using azathioprine or similar medicines to treat Crohn's disease or ulcerative colitis.

What should I discuss with my healthcare provider before taking azathioprine?

You should not take this medicine if you are allergic to azathioprine, or if you are pregnant (unless the benefits of treating you outweigh any risks posed by taking azathioprine). Some people using azathioprine have developed a rare fast-growing type of lymphoma (cancer). This condition affects the liver, spleen, and bone marrow, and it can be fatal. This has occurred mainly in teenagers and young adults using azathioprine or similar medicines to treat Crohn's disease or ulcerative colitis. However, people with autoimmune disorders (including rheumatoid arthritis, Crohn's disease, ankylosing spondylitis, and psoriasis) may have a higher risk of lymphoma. Talk to your doctor about your individual risk.

While taking azathioprine, you may have a higher risk of developing skin cancer. Talk to your doctor about this risk and what skin symptoms to watch for. To make sure azathioprine is safe for you, tell your doctor if you have: liver disease; any type of viral, bacterial, or fungal infection; if you have received a kidney transplant; or if you have recently received chemotherapy treatments with medications such as cyclophosphamide (Cytoxan), chlorambucil (Leukeran), melphalan (Alkeran). FDA pregnancy category D. Do not use azathioprine if you are pregnant. It could harm the unborn baby. Use effective birth control, and tell your doctor if you become pregnant during treatment. Azathioprine can pass into breast milk and may harm a nursing baby. You should not breast-feed while you are using azathioprine. This medication can affect fertility (your ability to have children), whether you are a man or a woman. Talk with your doctor if you have concerns about this.

How should I take azathioprine?

Your doctor may perform blood tests to make sure you do not have conditions that would prevent you from safely using azathioprine. Follow all directions on your prescription label. Your doctor may occasionally change your dose to make sure you get the best results. Do not take this medicine in larger or smaller amounts or for longer than recommended. Take azathioprine with food to lessen stomach upset. You may not be able to continue taking other arthritis medications together with azathioprine. Follow your doctor's dosing instructions very carefully. Azathioprine can lower blood cells that help your body fight infections and help your blood to clot. This can make it easier for you to bleed from an injury or get sick from being around others who are ill. Your blood will need to be tested often. It may take up to 8 weeks before your symptoms improve. Keep using the medication as directed and tell your doctor if your symptoms do not improve. If you need surgery, tell the surgeon ahead of time that you are using azathioprine. You may need to stop using the medicine for a short time. Store at room temperature away from moisture, heat, and light. Keep the bottle tightly closed when not in use.

What happens if I miss a dose?

Take the missed dose as soon as you remember. Skip the missed dose if it is almost time for your next scheduled dose. Do not take extra medicine to make up the missed dose.

What happens if I overdose?

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

What should I avoid while taking azathioprine?

Avoid being near people who are sick or have infections. Tell your doctor at once if you develop signs of infection. Avoid exposure to sunlight or tanning beds. Azathioprine can increase your risk of developing skin cancer. Wear protective clothing and use sunscreen (SPF 30 or higher) when you are outdoors. Do not receive a "live" vaccine while using azathioprine. The vaccine may not work as well during this time, and may not fully protect you from disease. Live vaccines include measles, mumps, rubella (MMR), rotavirus, typhoid, yellow fever, varicella (chickenpox), zoster (shingles), and nasal flu (influenza) vaccine.

Azathioprine side effects

Get emergency medical help if you have any of these signs of an allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue, or throat. Stop using azathioprine and call your doctor right away if you have any of these symptoms of lymphoma: fever, night sweats, weight loss, tiredness; feeling full after eating only a small amount; pain in your upper stomach that may spread to your shoulder; or easy bruising or bleeding, pale skin, feeling light-headed or short of breath, rapid heart rate. Azathioprine may cause a serious viral infection of the brain that can lead to disability or death. Call your doctor right away if you have any change in your mental state, decreased vision, or problems with speech or walking. These symptoms may start gradually and get worse quickly. Also call your doctor at once if you have: signs of infection (fever, chills, sore throat, body aches, weakness, muscle pain, flu symptoms); severe nausea, vomiting, or diarrhea; pain or burning with urination; white patches or sores inside your mouth or on your lips; or liver problems--nausea, upper stomach pain, itching, tired feeling, loss of appetite, dark urine, clay-colored stools, jaundice (yellowing of the skin or eyes). Common side effects may include: mild upset stomach, nausea, diarrhea, loss of appetite; hair loss; or skin rash.

Azathioprine dosing information

Usual Adult Dose for Renal Transplant:

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

Comments: -In a minority of cases, therapy has been started 1 to 3 days before transplantation & -The dose should not be increased to toxic levels because of threatened rejection, Use: Adjunctive therapy for prevention of rejection in renal homotransplantation.

Usual Adult Dose for Rheumatoid Arthritis:

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

Comments:
-Dose may be increased by 0.5 mg/kg/day (or approximately 25 mg/day), after 6 to 8 weeks of starting treatment and thereafter at 4 week intervals if necessary.
-Gradual dose reduction is recommended to reduce the risk of toxicities.
-Therapeutic response occurs after several weeks of therapy, usually 6 to 8 weeks. Patients not improved after 12 weeks can be considered refractory. 
-Azathioprine may be continued long-term in patients with clinical response.

Usual Adult Dose for Crohn's Disease -- Acute:

Studies:
1.5 to 4 mg/kg per day for 10 days up to 52 weeks

Usual Adult Dose for Crohn's Disease -- Maintenance:

Studies:
1.5 to 4 mg/kg per day for 10 days up to 52 weeks

Usual Adult Dose for Chronic Inflammatory Demyelinating Polyradiculoneuropathy:

Study (n=14)
2 to 3 mg/kg orally once a day for 9 months

Usual Adult Dose for Atopic Dermatitis:

Study (n=37)
2.5 mg/kg orally once a day, in the morning, for 3 months

Usual Adult Dose for Sarcoidosis:

Study (n=11)
Initial dose: 2 mg/kg per day in combination with prednisolone 0.6 to 0.8 mg/kg per day, with prednisolone reduced to 0.1 mg/kg within 2 to 3 months
Maintenance dose: 2 mg/kg per day with prednisolone 0.1 mg/kg per day for 21 to 22 months

Usual Adult Dose for Ulcerative Colitis:

Study (n=9)
IV: 20 to 40 mg/kg via IV infusion over 36 hours or 40 mg/kg as three 8-hour infusions over 3 days followed by oral azathioprine
Oral: 2 mg/kg orally per day beginning the day after completion of the IV loading dose

Study (n=12)
50 mg per day for 2 weeks, then 2 to 2.5 mg/kg per day plus mesalamine 500 mg orally 3 times a day; these drugs were started immediately after signs of remission was achieved (mean: 14.5 days) with cyclosporine IV (4 mg/kg/day)

Usual Adult Dose for Uveitis:

Study (n=14)
Treatment of choroidal neovascularization: 1 to 1.5 mg/kg orally per day, in combination with prednisolone and cyclosporine

Usual Adult Dose for Multiple Sclerosis:

Study (n=6)
Patients refractory to interferon beta-1b:
Initial dose: Azathioprine should be titrated up to 1.5 mg/kg per day over 1 month, followed by 50 mg increments in 6-month intervals, concomitantly with 8 million international units subcutaneous interferon beta-1b on alternate days
Maintenance dose: 2 mg/kg per day

Usual Adult Dose for Systemic Lupus Erythematosus:

Studies:
1 to 3 mg/kg actual body weight (ABW)/day orally or IV once a day

Study (n=55)
Diffuse proliferative lupus glomerulonephritis: Sequential therapy starting with prednisone (1 mg/kg/day) for 8 to 10 weeks, gradually tapering to maintenance dosage of 5 to 10 mg/day, together with oral cyclophosphamide (1 to 2 mg/kg/day) for 6 to 9 months followed by azathioprine 50 to 100 mg/day

Usual Adult Dose for Chronic Active Hepatitis:

Study (n=72)
Autoimmune hepatitis: 1 to 2 mg/kg per day, concomitantly with prednisolone (5 to 15 mg/day) for a minimum of 1 year (average 5 years)

Usual Adult Dose for Takayasu's Arteritis:

Study (n=15)
2 mg/kg ABW/day for 1 year in combination with prednisolone taper

Usual Pediatric Dose for Atopic Dermatitis:

Study (n=37)
Greater than 17 years: 2.5 mg/kg orally once a day, in the morning, for 3 months

Usual Pediatric Dose for Organ Transplant -- Rejection Prophylaxis:

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

Usual Pediatric Dose for Eczema:

Study (n=91)
Greater than 6 years: 2.5 to 3.5 mg/kg per day in patients with normal levels of thiopurine methyltransferase

Usual Pediatric Dose for Systemic Lupus Erythematosus:

Case Study (n=67)
Lupus Nephritis:
Greater than 5 years: 2 to 3 mg/kg per day (maximum dose: 150 mg/day)
Dose should be titrated to maintain a total white blood cell count between 3 and 4 x 10(3) cells/mL.

What other drugs will affect azathioprine?

Tell your doctor about all medicines you use, and those you start or stop using during your treatment with azathioprine, especially: allopurinol; a blood thinner (warfarin, Coumadin, Jantoven); or blood pressure medicine (benazepril, captopril, enalapril, lisinopril, quinapril, ramipril, trandolapril, and others). This list is not complete. Other drugs may interact with azathioprine, including prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible interactions are listed in this medication guide.