- Evidence of liver disease as indicated by abnormal liver function tests such as SGOT, SGPT, GGT, alkaline phosphatase, or serum bilirubin. SGOT, SGPT, GGT and alkaline phosphatase must not exceed twice the upper limit of the normal range, and serum bilirubin should not exceed the value of 27 µmol/L (1.6 mg/dL).