What is this medication for?
Azathioprine belongs to the group of medicines known as immunosuppressive agents. Azathioprine is used to prevent the rejection of kidney transplants by suppressing (turning down) the body's natural defense, or immune system. It is also used in the management of active rheumatoid arthritis, which is thought to be caused by the body's own immune system attacking the joints of the body.
Your doctor may have suggested this medication for conditions other than those listed here. As well, some forms of this medication may not be used for all of the conditions discussed here. If you have not discussed this with your doctor or are not sure why you are taking this medication, speak to your doctor. Do not give this medication to anyone else, even if they have the same symptoms as you do. It can be harmful for people to take this medication if their doctor has not prescribed it. Do not stop taking this medication without consulting your doctor.
What form(s) does this medication come in?
Azathioprine by Genpharm is available as:
Some medications may have other generic brands available. Always ask your doctor or pharmacist about the safety of switching between brands of the same medication.
How should I use this medication?
Azathioprine is available in tablet and injectable form. When used to prevent kidney transplant rejection, azathioprine is usually started on the day of transplant with an intravenous (into the vein) injection. Dose varies according to patient circumstances. The initial dose is 3 mg to 5 mg per kilogram of body weight and then is then generally reduced to 1 mg to 3 mg per kilogram of body weight per day.
For treatment of rheumatoid arthritis, azathioprine is usually given at a dose of approximately 1 mg per kilogram of body weight (50 mg to 100 mg) per day by mouth, in a single daily dose or on a twice-daily schedule. The dose may be increased at about six to eight weeks and thereafter at four week intervals if the response is unsatisfactory and there are tolerable side effects. If no improvement occurs by 12 weeks, treatment is usually stopped. The maximum daily dose is 2.5 mg per kilogram of body weight per day.
Azathioprine tablets must be taken exactly as directed by your doctor. If you miss a dose and you are taking the pills once a day, do not take the missed dose at all, but go back to your regular dosing schedule. If you are taking pills more than once a day, take the missed dose as soon as you remember. If it is almost time for your next dose, skip the missed dose and go back to your regular schedule. Do not take a double dose to make up for a missed one.
Many things can affect the dose of medication that a person needs, such as body weight, other medical conditions, and other medications. If your doctor has recommended a dose different from the ones listed here, do not change the way that you are taking the medication without consulting your doctor.
Azathioprine tablets should be stored in a cool, dry place and protected from direct light.
Who should NOT take this medication?
Azathioprine should not be used by anyone who:
- is sensitive or allergic to azathioprine or to any of the ingredients
- has already used certain rheumatoid arthritis drugs (alkylating drugs like cyclophosphamide, chlorambucil, melphalan, etc.), since the risk of developing a tumor is increased
- is pregnant