Dapsone-induced hepatic complications: it's time to think beyond methemoglobinemia

Abstract

Drug-induced liver injury is an important cause of hepatotoxicity and poses a challenging clinical problem with respect to both diagnosis and management. Patients susceptible to hepatotoxicity on exposure to dapsone is constantly on the rise. Dapsone (4,4'-diaminodiphenylsulfone) is clinically used alone or in combination with rifampicin for the treatment of a variety of dermatological disorders such as acne, dermatitis herpetiformis, psoriasis, Toxoplasma gondii infections, leprosy and pneumocystis carinii pneumonia in AIDS patients. However, the clinical use of dapsone is limited because of dose-dependent adverse hematological reactions. The cholestatic injury caused by dapsone and its N- hydroxylated metabolites hinders bile flow and causes oxidative stress and hepatic necrosis, further, leading to hemolysis responsible for hepatitis due to iron overload in the liver. Hence, clinicians' awareness of the hepatotoxic potential of dapsone is highly warranted.

Keywords: Dapsone syndrome; N-hydroxylation; cholestasis; sulfone.