RESUMEN
Nitrofurantoin is an antibiotic commonly used for prophylaxis and treatment of urinary tract infections. Pulmonary and hepatic toxicity are rare side effects of this agent. The simultaneous occurrence of pulmonary fibrosis and chronic active hepatitis in a patient undergoing long-term nitrofurantoin therapy is reported. The presence of pulmonary toxicity was evidenced by infiltrates on chest radiographs and impaired diffusion capacity during pulmonary function tests. Prolonged elevation of liver enzyme concentrations together with the presence of increased antibody titers (anti-smooth muscle antibody, antinuclear antibody) was suggestive of chronic hepatitis, a diagnosis corroborated by liver biopsy findings. After discontinuation of nitrofurantoin therapy, the patient had a full recovery. The infiltrates initially found on chest radiographs disappeared, and laboratory parameters normalized without the need for corticosteroid therapy.