Intentional dapsone overdose: a rare cause of acquired methaemoglobinaemia in the emergency department

Abstract

A woman in her 30s presented to our emergency department with vomiting and lethargy after an intentional ingestion of unknown antimicrobial pills which was later found to be dapsone. The patient developed cyanosis, hypoxia and tachycardia due to acute methaemoglobinaemia (level of 30.9% on venous blood gas analysis). As dapsone is notorious for prolonged and rebound methaemoglobinaemia, she was managed with repeated doses of intravenous methylene blue and oral multidose activated charcoal which warranted elective intubation and intensive care unit admission. Subsequent drug-induced hepatitis and delayed dapsone-induced haemolysis were managed conservatively. She was discharged in a stable condition with outpatient follow-ups. Physician familiarity with the nuances of this rare condition and its complications contributes to better patient care.