is prescribed in various conditions like for prevention of organ transplant and various auto immune diseases.
If you are tolerating the drug well without any side effects and if your blood counts and liver
function tests are normal,then you should keep taking the drug.
Generally this drug is given for many years.
Data suggests that it is safe to use for 5 years and may be for many more years.
Keep in regular contact with your treating doctor,have faith in him and abide by his instructions.