The Utility of Rifampin in Diagnosing Gilbertʼs Syndrome

Abstract

Rifampin increases total serum bilirubin levels in patients with and without Gilbert's syndrome. On fasting for 12 to 24 h, an absolute increase of bilirubin to >1.9 mg/dl 2 to 6 h after the administration of 900 mg of rifampin distinguishes patients with Gilbert's syndrome from those without it. In the nonfasting state, an increase in total serum bilirubin to > 1.5 mg/dl 4 to 6 h after the administration of rifampin distinguishes persons with Gilbert's syndrome from those without it.