Approved by the FDA in the 70s to treat endometriosis, danazol 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% of patients achieved a partial or complete response, however severe adverse effects were seen in almost 20% of the participants.2 ITP patients can take from three to six months to respond.3

Dosage

200 mg. 2-4 times daily.3

Side Effects

Because it is a male hormone, it can have a masculizing effect in females, promoting unwanted hair growth, deepening the voice, and decreasing breast size. In men it can effect sperm production. Danazol can cause fluid retention which could be a factor in those with other conditions exacerbated by increased fluid volume such as coronary disease, kidney disease and migraines.4

Precautions

It is not to be used in pregnant women, those about to become pregnant, or women who are breastfeeding.4

Danocrine 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

1. http://en.wikipedia.org/wiki/Danazol
2. http://www.ncbi.nlm.nih.gov/pubmed/15093754
3. ITP guidelines
4. http://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?id=4408