Azathioprine is used on its own or together with other medicines to prevent the rejection of organ or tissue after transplant.
This medicine may also be used to manage the signs and symptoms of rheumatoid arthritis (joint pain and swelling disorder).
Azathioprine may be used to treat other conditions as decided by your doctor.
Take Azathioprine exactly as directed by your doctor or according to the instructions on the label. Do not take more or less than instructed by your doctor.
You may take this medicine with or without food. Taking it with food or after meal may reduce stomach discomfort. Try to take it at the same time each day.
Azathioprine must be taken regularly for it to be effective. Continue taking this medicine even when you feel better. Do not stop taking it unless instructed by the doctor.
Take the missed dose as soon as you remember. If it is almost time for your next dose, skip the missed dose and return to your normal dosing schedule.
DO NOT double a dose under any circumstances.
If you often forget to take your medicine, let your doctor or pharmacist know.
Do not take Azathioprine if you have a history of allergic reactions (swollen eyes or mouth, difficulty breathing, rashes) to this medicine or any similar medicines such as mercaptopurine.
This medicine should not be used to treat rheumatoid arthritis in pregnant women.
Do not take Azathioprine if you are pregnant or planning to have a baby soon. If you become pregnant while being treated with this medicine, alert your doctor immediately. This medicine may cause harm to your unborn child. You must use proven birth control methods while taking this medicine.
Do not breastfeed while you are being treated with Azathioprine.
Do not take this medicine if you have rheumatoid arthritis and have been previously treated with the following medicines : cyclophosphamide, chlorambucil, melphalan.
Inform your doctor if you have the following conditions:
- liver disease
- kidney disease
Individuals who are poor metabolisers of TPMT or have NUDT15 gene mutation may experience enhanced side effects of this medicine e.g. myelosuppression, a bone marrow disorder leading to decreased blood cells production. Monitor for any signs of infection, unexpected bruising or bleeding and let your doctor know immediately. Your doctor may need to perform genetic testing before giving you this medicine to know if it is suitable for you. If you know you have this gene type, inform your doctor.
For as long as you are taking this medicine, your doctor will need to monitor you for any signs and symptoms of malignancies and infections. Your doctor may also need to do regular blood tests (e.g. complete blood counts, liver function tests) to check your body's response to the medicine. Your doctor will advise you about how often you will need to have tests.
Azathioprine may cause any of the following side effects: nausea, vomiting, diarrhoea, muscle pain, and general tiredness.
This medicine may also cause your skin to be more sensitive to sunlight. Avoid direct or long hours of exposure to the sun and other forms of ultraviolet (UV) light like tanning beds or sun lamps. Use a sunscreen and protective clothing when you go out into the sun.
Some side effects may need immediate medical help. Alert your doctor quickly if you experience any of the following:
- fever with persistent sore throat or mouth ulcers, unusual bleeding or bruising
- yellowing of the skin or eyes
Inform your doctor if any of these side effects do not go away or are severe, or if you experience other side effects.
Inform your doctor and pharmacist if you are taking any of these medicines:
- medicines for blood clot e.g. warfarin
- medicines for cancer e.g. mercaptopurine
- medicines for gout e.g. allopurinol
- medicines for high blood pressure e.g. enalapril, captopril, lisinopril
- medicines for bowel inflammation e.g. sulfasalazine, olsalazine, mesalazine
- medicines for bacterial infections e.g. cotrimoxazole
- medicines for viral infections e.g. ribavirin
This list does not include all medicines that may interact with Azathioprine.
Always inform your doctor and pharmacist if you are taking any other medicines, including herbal tonics such as traditional Chinese medicines, supplements and medicines that you buy without a prescription.
Store in a cool, dry place away from the reach of children.
Medicines must not be used past the expiry date.
Always return any unused or expired Azathioprine tablets to the clinic, hospital or pharmacy for disposal. Do not throw it away in the household waste.