Long-term use of azathioprine may rarely increase your risk of developing certain types of cancer (e.g., skin cancer, lymphoma). 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). You must be closely monitored by your doctor during treatment and regularly afterwards if your doctor stops treatment with this medication.
Azathioprine may also cause serious (rarely fatal) blood disorders (decreased bone marrow function leading to anemia, low number of white blood cells and platelets). It can lower your body's ability to fight an infection.
Keep all medical and laboratory appointments. Tell your doctor right away if you develop any of the following signs: unusual skin changes, change in the appearance/size of moles, unusual growths/lumps, swollen glands, swollen or painful abdomen, unexplained weight loss, night sweats, unexplained itching, signs of infection (e.g., fever, persistent sore throat), easy bruising/bleeding, or unusual tiredness.Who should not take azathioprine?
Azathioprine is used with other medications to prevent rejection of a kidney transplant. It works by weakening your body's defense system (immune system) to help your body accept the new kidney as if it were your own. This medication belongs to a class of drugs known as immunosuppressants.
Azathioprine is also used to treat patients with severe rheumatoid arthritis who have not responded to other medications (e.g., nonsteroidal anti-inflammatory drugs/NSAIDs such as ibuprofen). Rheumatoid arthritis is thought to be caused by the immune system attacking the joints. Early treatment of rheumatoid arthritis with more aggressive therapy such as azathioprine helps to reduce further joint damage and to preserve joint function.
Talk to the doctor about the risks and benefits of azathioprine, especially when used in children and young adults.
OTHER USES: This section contains uses of this drug that are not listed in the approved professional labeling for the drug but that may be prescribed by your health care professional. Use this drug for a condition that is listed in this section only if it has been so prescribed by your health care professional.
This medication may also be used to prevent rejection of other transplanted organs, to treat certain types of bowel conditions (Crohn's disease, ulcerative colitis) that is not responsive to usual treatment, and to treat other immune system problems (autoimmune diseases) as determined by your doctor.
Take this medication by mouth, usually once or twice daily as directed by your doctor. Azathioprine should be taken with food to reduce stomach upset. Dosage is based on your medical condition, weight, and response to therapy. For the treatment of rheumatoid arthritis, the manufacturer recommends that you do not take more than 2.5 milligrams per kilogram per day.
Do not increase your dose or take this medication more often without your doctor's approval. Your condition will not improve any faster and the risk of serious side effects may be increased. Also do not stop taking this medication without your doctor's approval.
Use this medication regularly in order to get the most benefit from it. Remember to use it at the same time(s) each day.
For arthritis, it may take up to 2 months of continued use to notice relief of symptoms. Inform your doctor if your condition does not improve after 3 months of treatment.
Since this drug can be absorbed through the skin, women who are pregnant or who may become pregnant should not handle or break the tablets of this medication.
See also Warning section.
Remember that your doctor has prescribed this medication because he or she has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.
You may experience stomach/intestinal symptoms such as nausea, vomiting, diarrhea, or loss of appetite. If these effects persist or worsen, notify your doctor right away. These symptoms may be reduced by taking the medication after meals. Talk to your doctor or pharmacist about other dosing advice that may also help with these symptoms.
Although unlikely, more severe stomach/intestinal symptoms (e.g., severe nausea/vomiting/diarrhea, stomach/abdominal pain) may occur as part of a very serious allergic reaction. Seek immediate medical attention if you have severe stomach/intestinal symptoms or other symptoms of a serious allergic reaction which may include: fever, shaking chills, rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing, cough, new or worsening joint/muscle aches, dark urine.
Tell your doctor right away if any of these unlikely but serious side effects occur: muscle loss, hair loss, cold/numbness in the fingers, mouth sores, difficult/painful swallowing, greasy stools.
Seek immediate medical attention if any of these rare but very serious side effects occur: yellowing eyes/skin, swelling/extra fluid around the abdomen, vomit that contains blood or looks like coffee grounds, black stools.
This medication may increase your risk of getting a rare but very serious (sometimes fatal) brain infection (progressive multifocal leukoencephalopathy-PML). Get medical help right away if any of these rare but very serious side effects occur: clumsiness, loss of coordination, weakness, sudden change in your thinking (such as confusion, difficulty concentrating), difficulty moving your muscles, problems with speech, seizure, vision changes.
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.
In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.
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, blood disorders, decreased bone marrow function, history of cancer (such as lymphoma), active infections, certain enzyme disorder (TPMT deficiency).
Do not have immunizations/vaccinations without the consent of your doctor, and avoid contact with people who have recently received polio vaccine by mouth or flu vaccine inhaled through the nose.
Since this medication can increase your risk of developing serious infections, wash your hands well to prevent the spread of infections. Avoid contact with people who have illnesses that may spread to others (e.g., flu, chickenpox).
Use caution with sharp objects like safety razors or nail cutters, and avoid activities such as contact sports to lower the chance of getting cut, bruised, or injured.
Kidney function declines as you grow older. This medication is removed by the kidneys. Therefore, the elderly may be more sensitive to the effects of this drug.
This medication is not recommended for use during pregnancy. It may harm an unborn baby. Discuss the use of reliable forms of birth control (such as condoms, birth control pills) with your doctor. This medication can decrease the effectiveness of intrauterine devices (IUDs). This can result in pregnancy. Talk to your doctor about other reliable birth control choices.
This medication passes into breast milk and may have undesirable effects on a nursing infant. Therefore, breast-feeding while using this drug is not recommended. Consult your doctor before breast-feeding.
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 include: ACE inhibitors (e.g., benazepril, lisinopril), allopurinol, aminosalicylates (e.g., mesalamine, olsalazine, sulfasalazine), "blood thinners" (e.g., enoxaparin, heparin, warfarin), drugs affecting the bone marrow (e.g., trimethoprim/sulfamethoxazole, cancer chemotherapy drugs), febuxostat, past or present use of alkylating-type cancer drugs (e.g., chlorambucil, 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.
If overdose is suspected, contact a poison control center or emergency room 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.
Do not share this medication with others.
Laboratory and/or medical tests (e.g., complete blood count, liver and kidney function) should be performed periodically to monitor your progress or check for side effects. Consult your doctor for more details.
If you have had an organ transplant, it is recommended that you attend a transplant education class or support group. Learn the signs of organ rejection such as a feeling of being ill, fever, or tenderness around the transplanted organ. Signs of a failing kidney transplant include a decrease in the amount of urine, swelling of the arms/legs/face, trouble breathing, or increase in blood pressure. Seek immediate medical attention if these symptoms occur.
Unless your doctor directs you otherwise, if you take this drug once daily and miss a dose, take it as soon as you remember unless it is almost time for the next dose. If it is near the time of the next dose, skip the missed dose and resume your usual dosing schedule. Do not double the dose to catch up.
If you take more than one dose a day and miss a dose, take it as soon as you remember. If it is almost time for the next dose, take both doses together, then resume your usual dosing schedule. If you miss more than one dose, contact your doctor. You may need to have your dosing schedule adjusted.
Store at room temperature between 59-77 degrees F (15-25 degrees C) away from light and moisture. Do not store in the bathroom. Keep all medicines 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 for more details about how to safely discard your product.
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 December 2014. Copyright(c) 2014 First Databank, Inc.
With WebMD's Medicine Cabinet, you can check interactions with drugs.Go to medicine cabinet