The association between rifamycin-SV (R-SV) related hyperbilirubinaemia and antipyrine clearance as a new test of liver function in cirrhosis.

Several clearance tests have been used to assess the residual hepatic efficiency in liver cirrhosis. However, the altered clearance values found in cirrhotic patients may reflect not only the impairment in liver function but also a derangement in the hepatic blood-flow. Therefore, this study was designed to explore the possibility that the competition between Rifamycin-SV and bilirubin at the hepatic uptake site might be used as an index for quantitative assessment of residual hepatic efficiency in 48 patients with chronic liver disease. In this test, the interference of hepatic blood flow would be negligible. Antipyrine clearance was also evaluated in the same subjects in order to explore the cytoplasmic microsomal efficiency. Rifamycin-SV intravenous load was followed by a sustained increase in bilirubinaemia which significantly related with the degree of liver function as assessed by the Child-Pugh criteria. Also, antipyrine clearance was significantly altered in cirrhotic patients compared to controls. Moreover, a positive correlation was found between the Rifamycin-SV test and Antipyrine clearance. We suggest that a combination of these tests might be of use in the quantitative assessment of liver function.