[Constitutional syndrome associated to metformin induced hepatotoxicity].

Metformin is an oral antidiabetic agent frequently used to manage type II diabetes. This drug produces nonspecific gastrointestinal symptoms in 5-20% of patients and, more rarely, has also been associated with severe adverse effects such as lactic acidosis. Only a few isolated cases of hepatotoxicity due to this drug have been documented. We report the case of an 83-year-old man with constitutional syndrome and hepatic biochemical alterations, which were attributed to metformin after ruling out an oncologic etiology and observing complete clinical and biochemical resolution after withdrawal of the drug.