Autoimmune hepatitis triggered by nitrofurantoin: A rare drug-induced toxicity

Nitrofurantoin is a commonly used drug which can have liver and pulmonary adverse effects. Among hepatic nitrofurantoin-induced adverse effects, autoimmune hepatitis is a rare complication which must not be mistaken as a toxic hepatitis. We report an 86-year-old woman who presented with acute hepatitis after a 3-month course of nitrofurantoin administration for urinary tract infections. She reported a previous hepatitis after treatment by nitrofurantoin twenty years before. Biological analysis showed polyclonal hypergammaglobulinemia, positive test for antinuclear antibodies and smooth muscle antibodies. Finally, liver histology showed lymphocytic infiltration, marked necrotic and inflammatory activity consistent with the diagnosis of autoimmune hepatitis. Nitrofurantoin was discontinued. Outcome of autoimmune hepatitis was good with corticosteroids and azathioprine but two months later, the patient died from a refractory global heart failure. Nitrofurantoin-induced autoimmune hepatitis is a severe condition which must be systematically discussed in patients taking nitrofurantoin who present with acute hepatitis. Hypergammaglobulinemia is an easily obtained blood marker, which can suggest this diagnosis. Treatment relies on nitrofurantoin eviction, corticosteroids and sometimes azathioprine. Outcome is usually favorable.