Acute hemorrhagic colitis induced by the oral administration of oseltamivir used for influenza A treatment

Abstract

A 40-year-old woman with a history of bronchial asthma was diagnosed with influenza A using a rapid diagnosis kit. She began to experience abdominal pain, diarrhea, and hematochezia approximately 4 hours after a single capsule of oseltamivir had been administered. Colonoscopic findings indicated circumferential hemorrhagic colitis with longitudinal erosions in the descending colon, findings which mimicked those of ischemic colitis ([Fig. 1]). Histopathological analysis of the lesion showed the presence of mucosal hemorrhage and submucosal edema ([Fig. 2]). Stool culture showed normal flora. Discontinuation of the oseltamivir therapy was followed by an immediate improvement in the hemorrhagic colitis. The lymphocyte transformation test (LTT) yielded positive results for oseltamivir only, with negative results for the other drugs administered, which included clarithromycin and acetaminophen.