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Azathioprine |
Azathioprine tablets are used as an immunosuppressant antimetabolite either alone or, more commonly, in combination with other agents (usually corticosteroids) and procedures which influence the immune response. Therapeutic effect may be evident only after weeks or months and can include a steroid-sparing effect, thereby reducing the toxicity associated with high dosage and prolonged usage of corticosteroids.
BEFORE USING YOUR MEDICINE
Tell your doctor before you start taking Azathioprine if the answer to any of the following questions is yes:
1. Do you suspect that you have had an allergic reaction to,
or been upset by any of the ingredients in Azathioprine (listed in "WHAT'S
IN YOUR MEDICINE")?
2. Do you have any kidney problems or have you had any disease, which may have
affected your kidneys?
3. Do you have an infection of any type?
4. Have you been told that you have any kind of tumour?
5. Do you have any liver problems or have you had any disease, which may have
affected your liver?
6. Have you been told that you that you have gout?
Are you taking any other medicines (either bought or prescribed)?
Some medicines can interfere with your treatment, so make sure to check with your doctor or pharmacist before taking any other medicines. In particular, tell your doctor if you are taking any of the following:
1) Allopurinol/oxipurinol/thiopurinol
2) Neuromuscular blocking agents:
3) Warfarin
4) penicillamine,
5) co-trimoxazole.
6) Captopril.
7) Cimetidine
8) Indomethacin
9) Aminosalicylate derivatives (eg. olsalazine, mesalazine or sulphasalazine)
10) Vaccines: Live vaccines should be avoided and there may be a poor response
to killed vacccines.
TAKING YOUR MEDICINE
1) Your doctor will work out the correct dose of Azathioprine
for you depending on your body weight
2) In general, starting dosage is from 1 to 3 mg/kg bodyweight/day, and is
adjusted, within these limits, depending on the clinical response (which may not
be evident for weeks or months) and the blood tests.
OVERDOSE
Unexplained infection, ulceration of the throat, bruising and bleeding are the main signs of overdosage with Azathioprineand result from bone marrow depression which may be maximal after 9 to 14 days. These signs are more likely to be manifest following chronic overdosage, rather than after a single acute overdose.
AFTER TAKING YOUR MEDICINE
Most people benefit from taking this medicine, but a few
people can be upset by it.
The dose of this medicine needs to be carefully adjusted by your doctor. Too
much can affect the blood and the liver. You will, therefore, have regular blood
tests and visits to the hospital or your GP. This will give you the chance to
talk to your doctor about your treatment and mention any problems you are
having.
First two months
Weekly blood tests are required as azathioprine may affect the production of
blood cells by the bone marrow. It is suggested that during the first 8 weeks of
therapy, complete blood counts, including platelets, should be performed weekly.
Tell your doctor if you have any of the following symptoms:
1) Feeling sick and/ or being sick
2) Diarrhoea
3) Fever, shivering/chill and skin rash
4) Muscle and bone pain
5) Kidney problems
6) Tiredness, dizziness
Tell your doctor immediately if any of the following happen:
1) You start to notice any signs of fever or an infection
2) You have unexpected bruising or bleeding
3) Your skin or the whites of your eyes turn yellow
4) You develop a chest infection
Some patients experience nausea when first given Azathioprine. This appears to be relieved by administering the tablets after meals.
In the long run
Reversible pneumonitis has been described very rarely.
Hair loss has been described on a number of occasions in patients receiving
azathioprine and other immunosuppressive agents. In many instances the condition
resolved spontaneously despite continuing therapy. The relationship between
alopecia and azathioprine treatment is uncertain.
A rare, but life-threatening hepatic veno-occlusive disease associated with
chronic administration of azathioprine has been described, primarily in
transplant patients. In some cases withdrawal of azathioprine has resulted in
either a temporary or permanent improvement in liver histology and symptoms.
Pregnancy and Breast Feeding
Azathioprineshould not be given during pregnancy without
careful assessment of risk versus benefit.
Azathioprine and/or its metabolites have been found in low concentrations in
foetal blood and amniotic fluid after maternal administration of azathioprine.
Low white cell counts (fight infection) and low platelet counts (help the blood
clot) have been reported in a proportion of neonates whose mothers took
azathioprine throughout their pregnancies. Extra care in haematological
monitoring is advised during pregnancy.
6-Mercaptopurine has been identified in the colostrum and breast-milk of women
receiving azathioprine treatment.