Dapsone-induced methemoglobinemia leading to nystagmus

Abstract

Dapsone, classified as a sulfonamide antibiotic, has been found to be useful in an array of infectious as well as inflammatory diseases. Neuropathy, agranulocytosis, hypersensitivity, methemoglobinemia, hemolysis, and jaundice are the most common potential side effects of dapsone when taken at high doses. We present a case report of an extremely rare side effect of dapsone overdose in a man due to accidental ingestion, resulting in methemoglobinemia associated with bilateral gaze evoked horizontal nystagmus. The patient was taking dapsone for the treatment of leprosy. Methemoglobinemia is a known side effect of dapsone therapy; nystagmus is rarely seen in dapsone overdose. The patient recovered completely after receiving treatment with multiple drugs and had no nystagmus, implying that dapsone-induced nystagmus is reversible in nature. Dapsone is a drug that has potent anti-inflammatory, antiparasitic, and antibacterial properties and it has found to be useful in the treatment of multiple diseases. The purpose of documenting this case report is to bring to the attention of physicians and others involved in patient care the serious side effects of dapsone.