Immunosuppressants, including azathioprine (Imuran®), cyclosporine (Sandimmune®), diphenylsulfone (Dapsone®), Sirolimus (Rapamycin ®), and mycophenolate mofetil (Cellcept®), are considered a second or third-line treatment for ITP. This class of drugs is used to treat other autoimmune diseases, including multiple sclerosis (MS) and lupus, but none have gained FDA approval to treat ITP.

A class of drugs that suppress, or reduce, the strength of the body’s immune system, immunosuppressants are also referred to as anti-rejection drugs because they are used to make the body less likely to reject a transplanted organ, such as a liver, heart or kidney.

Azathioprine (Imuran, Azamun)

Azathioprine suppresses the division of white blood cells,1  but is slow to raise the platelet count and should be continued for about four months before determining whether it has been effective. It is sometimes given along with the corticosteroid prednisone.2 

Side effects include excessive tiredness, pale skin, headache, confusion, dizziness, fast heartbeat, difficulty sleeping, weakness, shortness of breath, sore throat, fever, chills, and other signs of infection.3

Imuran can cause irreversible bone marrow failure for those with a particular polymorphism of the TPMT gene. GlaxoSmithKline has a DNA test to predict this possibility.

Cyclosporine (Sandimmune)

Cyclosporine blocks the action of T-cells, a type of white blood cell responsible for fighting infections.4 For patients with ITP, the response rate in one study was 55 percent, but the relapse rate was high.7 

Cyclosporine may damage the kidneys, raise blood pressure and increase your risk of developing cancer. Side effects include flu-like symptoms, coughing, difficult or painful urination, changes in the skin, fatigue, and swollen glands.4

Grapefruit juice and perhaps citrus sodas can increase the level of circulating cyclosporine.5 Research has shown St. John's wort reduces the concentration of cyclosporine, making it less effective.6

Mycophenolate mofetil (CellCept)

Mycophenolate mofetil inhibits the proliferation of B and T lymphocytes, types of white blood cells. In a small study of ITP patients, seven of 18 responded, but three of the seven responders had some lower platelet episodes while taking the medication.8 

Side effects include: bowel changes, insomnia, headache, dizziness, swelling, pain, difficulty breathing, rapid heartbeat, blood in stools or vomit.9 Extremely rare, but very serious side effects, include Pure Red Cell Aplasia, a type of anemia9 and progressive multifocal leukoencephalopathy, a rare, incurable neurological condition.10

A Word of Caution

Immunosuppressants should not be used in pregnant women, those about to become pregnant or women who are breastfeeding. These drugs can increase the risk of infections or activate latent viral infections, in addition to increasing the risk of developing certain types of cancer.3,4,9 

Before taking immunosuppressants, be sure to tell your doctor if you have ever had cancer or are taking other medications that suppress the immune system.4

Select a treatment table to view or download below.

Cyclosporine Treatment Tables
Imuran Treatment Tables
Mycophenolate Mofetil Treatment Tables
Dapsone Treatment Tables
Sirolimus Treatment Tables


  1. Wikipedia: Azathioprine
  2. Quiquandon I et al. “Re-evaluation of the role of azathioprine in the treatment of adult chronic idiopathic thrombocytopenic purpura: a report on 53 cases.” Br J Haematol. 1990 Feb;74(2):223-8.
  3. Medline Plus: Azathioprine
  4. Medline Plus: Cyclosporine
  5. Schwarz UI et al. “Impact of citrus soft drinks relative to grapefruit juice on ciclosporin disposition.” Br J Clin Pharmacol. 2006 Oct;62(4):485-91.
  6. Dasgupta A. “Herbal supplements and therapeutic drug monitoring: focus on digoxin immunoassays and interactions with St. John's wort.” Ther Drug Monit. 2008 Apr;30(2):212-7.
  7. Kappers-Klunne MC, van't Veer MB. “Cyclosporin A for the treatment of patients with chronic idiopathic thrombocytopenic purpura refractory to corticosteroids or splenectomy.” Br J Haematol. 2001 Jul;114(1):121-5.
  8. Provan D et al. “Efficacy of mycophenolate mofetil as single-agent therapy for refractory immune thrombocytopenic purpura.” Am J Hematol. 2006 Jan;81(1):19-25.
  9. Medline Plus: Mycophenolate 
  10. Wikipedia: Mycophenolic acid