Dapsone induced hemolysis and drop in saturation in normal glucose-6-phosphate dehydrogenase level patients - alarming presentation of poor man's drug: A series of 12 cases and review of literature.

BACKGROUND: Dapsone-induced hemolysis is well described in the literature, especially in glucose-6-phosphate dehydrogenase (G6PD) enzyme deficiency. However, it is reported rarely with normal G6PD levels. OBJECTIVES: The objective of the study was to describe the association between dapsone and fall in oxygen saturation (SpO2) and hemoglobin after intake of the drug. MATERIALS AND METHODS: All outpatients and inpatients receiving dapsone who presented with breathlessness, fall in SpO2, hemolysis, and fall in hemoglobin were included in the study. Patients who were started on dapsone were asked to measure the SpO2 regularly and observed for any breathlessness. Complete blood count (CBC) and liver function test (LFT) were repeated, and a reticulocyte test was done after 1 week of dapsone. RESULTS: Twelve cases (5 female and 7 male) with a mean age of 47 years, ranging from 22 to 83 years, presented with various dermatological conditions treated with dapsone. SpO2 fell in all cases, of which eight cases developed breathlessness after starting dapsone. Nine cases developed a reduction in hemoglobin (Hb) with increased reticulocyte counts. The mean decrease in Hb was 2.74 mg/dL. LFT was deranged postdapsone in six cases. Dapsone was stopped in all cases, following which Hb level improved, and there was relief of breathlessness with normal SpO2. Confirmation was done by drug provocation with dapsone. CONCLUSION: Baseline CBC and SpO2 with frequent repetition every week, along with reticulocyte count, are essential to look for dapsone induced hemolysis and methemoglobinemia.