1. How does it work?
Azathioprine works by decreasing the number of B and T cells, two type of white blood cells felt to cause inflammation and damage in NMOSD. Mechanistically this drug is most similar to Mycophenolate Mofetil.
2. Who should not take this drug?
Talk with your doctor about any potential contraindications to Azathioprine.
3. How is it taken?
Oral pill at home.
4. How often is it generally taken?
5. What is the typical dosage?
Dosage is based off of weight and white blood cell counts; typical dosing is around 2 to 3 mg/kg/day.
6. How much does it reduce my risk of relapse?
As a clinical trial has not been performed yet on these medications for NMOSD, the estimated relapse risk decrease has not been calculated. Like many other neurologic autoimmune conditions, physicians used this medication before there were FDA approved therapies available as a general immunosuppressant. It is still considered a standard of care and potential option for treatment of NMOSD by most doctors.
7. What are the side effects?
A flu like illness upon starting the medication, which improves with time. Other side effects include stomach upset, nausea, and vomiting. Blood cell numbers can be decreased, raising the risk of infections. There is a small risk of blood and skin cancers.
8. What should I do to prepare for taking this?
Your doctor should check your blood work for cell counts and liver enzymes. You should have a skin examination by a dermatologist.
9. What ongoing monitoring should occur when taking this drug?
You should have a skin examination by a dermatologist yearly. Your doctor should check your blood counts and liver enzymes at least twice per year.
10. Who makes this medication?
Azathioprine is produced by Pharmaceutics International.
11. How can I get help paying for it?
You can work with your doctor or local hospital’s social work department to try to get assistance covering these medications.
12. Can I take it if I’m pregnant?
No. Azathioprine is pregnancy category D, meaning this medication is not safe for use during pregnancy. It is associated with increased risks of pregnancy loss and congenital malformations.
13. Clinical trial information
Studies investigating Azathioprine have largely been retrospective and not placebo-controlled trials, but have indicated reductions in relapse rates for those with NMOSD.
14. Will my insurance cover it?
This will depend on your insurance company and the billing code your doctor uses. For specific questions, call the customer service phone number on the back of your insurance card with the name of the drug in question, as well as ICD (diagnostic) code your doctor uses.
15. Is it FDA approved for NMOSD?
No, it is used off-label.