Dapsone is one of the second line treatments of
immune thrombocytopenic purpura (
ITP).
Dapsone is cheap and has response rates comparable to other second line treatment options like
azathioprine,
danazol,
cyclophosphamide,
cyclosporine, and
vincristine. This retrospective analysis includes 38 patients (out of total 313 patients) of
ITP treated with
dapsone from 2004 to 2012. All male patients were screened for
G6PD deficiency before starting
dapsone. Out of 38 patients (12 children and 26 adults), one was newly diagnosed
ITP, seven were persistent
ITP, and 30 were chronic
ITP. Five patients had side effects of
dapsone; two required discontinuation due to skin rashes. The average dose of
dapsone was 1.57 mg/kg/day and time to response was 57 days (19-108 days). The response was irrespective of previous treatments and response to them. The response rate was 48.6% (complete response = 40.5%). Only two adult patients had sustained response (> 6 months) after
dapsone discontinuation. There were no predictors identified for
dapsone response.
Dapsone is a safe and cheap second-line
therapy for
ITP with a response rate of about 50% (majority being CR). A response to
dapsone is slow, sustained, and relapses are uncommon on
therapy.
Dapsone withdrawal leads to relapse in most of the patients.