Modified testosterone is a synthetic androgen (male sex hormone) sometimes used to treat ITP when other treatments have failed. Approved by the Food and Drug Administration (FDA) in the 1970s to treat endometriosis, the modified testosterone drug danazol (Danocrine®) is currently used to treat a number of diseases off-label, including ITP. It is a synthetic androgen (male sex hormone) that disrupts the production of estrogen.1
Danazol is considered a second-line treatment for ITP, used after other treatments are considered or fail. In a small trial, 67 percent of patients achieved a partial or complete response, however severe adverse effects were seen in almost 20 percent of the participants.2 ITP patients may take three to six months to respond.3
Danazol is a pill given at a dose of 200 milligrams (mg), two to four times daily (10 to 15 mg/kg/d).
Because it is a male hormone, danazol can have a masculinizing affect in females, promoting unwanted hair growth, deepening of the voice and decreasing breast size. In men, it can affect sperm production.
Danazol can cause fluid retention, which could be a factor in those with other conditions exacerbated by increased fluid volume including coronary disease, kidney disease and migraines.4
Older females and those without a spleen may have a higher response rate.2
A Word of Caution
Danazol is not to be used in pregnant women, those about to become pregnant or women who are breastfeeding.4 Danazol is metabolized in the liver and can elevate liver enzymes. It should not be given to those with liver problems and liver function should be checked periodically.4
- Wikipedia: Danazol http://en.wikipedia.org/wiki/Danazol
- Maloisel F et al. “Danazol therapy in patients with chronic idiopathic thrombocytopenic purpura: long-term results.” Am J Med. 2004 May 1;116(9):590-4. http://www.ncbi.nlm.nih.gov/pubmed/15093754
- Provan, D, “International consensus report on the investigation and management of primary immune thrombocytopenia,” Blood. 2010 Jan 14; 115 (2):168-86. http://bloodjournal.hematologylibrary.org/cgi/content/full/115/2/168
- Medline Plus: Danazol http://www.nlm.nih.gov/medlineplus/druginfo/meds/a682599.html