AZATHIOPRINE

Do NOT use Azathioprine if:

• you are allergic to any ingredient in Azathioprine
• you have a tumor or an unusual growth
• you have rheumatoid arthritis and are pregnant
• you are taking mercaptopurine
• you have rheumatoid arthritis and have used alkylating agents (eg, cyclophosphamide, chlorambucil, melphalan) in the past

Contact your doctor or health care provider right away if any of these apply to you.

Before using Azathioprine:

Some medical conditions may interact with Azathioprine. Tell your doctor or pharmacist if you have any medical conditions, especially if any of the following apply to you:

• if you are pregnant, planning to become pregnant, or are breast-feeding
• if you are taking any prescription or nonprescription medicine, herbal preparation, or dietary supplement
• if you have allergies to medicines, foods, or other substances
• if you have kidney or liver problems, or gout
• if you have an infection, a history of frequent or prolonged infections, or you have recently had a vaccination
• if you have a history of bone marrow problems, anemia, low white blood cell or platelet levels, or unusual bruising or bleeding
• if you have certain enzyme deficiencies (thiopurine methyltransferase [TPMT] or xanthine oxidase) or you have recently had a blood transfusion
• if you are taking a disease-modifying antirheumatic drug (DMARD) (eg, methotrexate, adalimumab)

Some MEDICINES MAY INTERACT with Azathioprine. Tell your health care provider if you are taking any other medicines, especially any of the following:

• Alkylating agents (eg, cyclophosphamide, chlorambucil, melphalan) because the risk of developing a tumor may be increased
• Mercaptopurine because severe toxic effects, including severe bone marrow suppression or death, may occur
• Allopurinol, aminosalicylates (eg, mesalazine, olsalazine, sulfasalazine), angiotensin-converting enzyme (ACE) inhibitors (eg, enalapril), doxorubicin, or trimethoprim/sulfamethoxazole because they may increase the risk of Azathioprine’s side effects
• Anticoagulants (eg, warfarin) or hydantoins (eg, phenytoin) because their effectiveness may be decreased by Azathioprine

This may not be a complete list of all interactions that may occur. Ask your health care provider if Azathioprine may interact with other medicines that you take. Check with your health care provider before you start, stop, or change the dose of any medicine.

How to use Azathioprine:

Use Azathioprine as directed by your doctor. Check the label on the medicine for exact dosing instructions.

• Take Azathioprine by mouth with or without food. If stomach upset occurs, take with food to reduce stomach irritation.
• Ask your doctor if you should follow any special guidelines for handling Azathioprine.
• If you miss a dose of Azathioprine, take it as soon as possible. If it is almost time for your next dose, skip the missed dose and go back to your regular dosing schedule. Do not take 2 doses at once.

Ask your health care provider any questions you may have about how to use Azathioprine.

Important safety information:

• Azathioprine may lower the ability of your body to fight infection. Avoid contact with people who have colds or infections. Tell your doctor if you notice signs of infection like fever, sore throat, rash, or chills.
• Azathioprine may reduce the number of clot-forming cells (platelets) in your blood. Avoid activities that may cause bruising or injury. Tell your doctor if you have unusual bruising or bleeding. Tell your doctor if you have dark, tarry, or bloody stools.
• Tell your doctor or dentist that you take Azathioprine before you receive any medical or dental care, emergency care, or surgery.
• Talk with your doctor before you receive any vaccine while you are taking Azathioprine.
• Contact your doctor at once if you develop severe nausea and vomiting. This may occur with or without diarrhea, rash, fever, muscle pain, or dizziness. If this reaction occurs, it usually happens within the first several weeks of therapy.
• Azathioprine may increase your risk of developing a tumor or other cancer. Contact your doctor at once if you notice any unusual growths or lumps. Discuss any questions or concerns with your doctor.
• An enzyme called TPMT helps to break Azathioprine down in the body. Infrequently, some patients may have decreased TPMT enzyme activity. This may increase the risk of developing serious side effects (eg, severe bone marrow problems). Patients with decreased TPMT enzyme activity may need a lower dose of Azathioprine. Discuss any questions or concerns with your doctor.
• Lab tests, including complete blood counts, liver function, and TPMT enzyme activity, may be performed while you use Azathioprine. These tests may be used to monitor your condition or check for side effects. Be sure to keep all doctor and lab appointments.
• Azathioprine should be used with extreme caution in CHILDREN; safety and efficacy in children have not been confirmed.
• PREGNANCY and BREAST-FEEDING: Azathioprine has been shown to cause harm to the fetus. Do not become pregnant while you are using it. If you think you may be pregnant, contact your doctor. You will need to discuss the benefits and risks of using Azathioprine while you are pregnant. Azathioprine is found in breast milk. Do not breast-feed while taking Azathioprine.

Possible side effects of Azathioprine:

All medicines may cause side effects, but many people have no, or minor, side effects. Check with your doctor if any of these most COMMON side effects persist or become bothersome:

Mild nausea or vomiting.

Seek medical attention right away if any of these SEVERE side effects occur:

Severe allergic reactions (rash; itching; hives; difficulty breathing; tightness in the chest; swelling of the mouth, face, lips, or tongue); chest pain or tightness; dark urine; dizziness; fever, chills, or sore throat; increased or painful urination; muscle pain or aches; pale or fatty stools; severe or persistent nausea, vomiting, or diarrhea; shortness of breath; stomach pain; unusual bleeding or bruising; unusual growths or lumps; unusual weakness or fatigue; yellowing of the eyes or skin.

This is not a complete list of all side effects that may occur. If you have questions about side effects, contact your health care provider. Call your doctor for medical advice about side effects.

If OVERDOSE is suspected:

Contact your local Poison Control or emergency room immediately.Symptoms may include severe or persistent diarrhea, nausea, or vomiting; unusual bruising or bleeding.

Proper storage of Azathioprine:

Store Azathioprine at room temperature, between 68 and 77 degrees F (15 and 25 degrees C), in a tightly closed container. Store away from heat, moisture, and light. Do not store in the bathroom. If you no longer need Azathioprine, ask your doctor how to properly dispose of it. Keep Azathioprine out of the reach of children and away from pets.

General information:

• If you have any questions about Azathioprine, please talk with your doctor, pharmacist, or other health care provider.
• Azathioprine is to be used only by the patient for whom it is prescribed. Do not share it with other people.
• If your symptoms do not improve or if they become worse, check with your doctor.
• Check with your pharmacist about how to dispose of unused medicine.

This information is a summary only. It does not contain all information about Azathioprine. If you have questions about the medicine you are taking or would like more information, check with your doctor, pharmacist, or other health care provider.