Plasma clearance of nicotinic acid and rifamycin-SV, and their interaction in Gilbert's syndrome: application of a compartmental model.

Abstract

The bicompartmental kinetics of nicotinic acid (NA) and rifamycin-SV (R-SV)--2 organic anions that probably share a common hepatic uptake mechanism--were studied in 7 cases of Gilbert's syndrome (GS) and in 7 healthy controls matched for sex and age. In GS the NA and R-SV uptake constants (K21) were significantly decreased. In GS patients, simultaneous loads of NA and R-SV, the latter at increasing doses, produced: 1) a progressive lowering only of R-SV K21; and 2) an increase in R-SV hepatic plasma reflux (K12). Changes in biliary excretion ( Kee ) and hepatocellular pool (Ke) of both NA and R-SV probably depend on the rates of uptake and reflux constants of the two anions. The study of the parameters of compartmental kinetics of NA and R-SV confirms that the two organic anions, which have different metabolic routes and/or a different affinity for intracellular carriers, share common uptake mechanisms.

• Authors: S Gentile, R Marmo, M Persico, P Bronzino, M Coltorti
• Journal: Hepato-gastroenterology (Hepatogastroenterology) Vol. 31 Issue 2 Pg. 72-5 (Apr 1984) ISSN: 0172-6390 [Print] Greece
• PMID: 6724499 (Publication Type: Journal Article)

Chemical References

• Rifamycins
• Niacin
• rifamycin SV

Topics

• Adolescent
• Adult
• Drug Interactions
• Female
• Gilbert Disease (blood)
• Humans
• Hyperbilirubinemia, Hereditary (blood)
• Kinetics
• Liver (metabolism)
• Male
• Metabolic Clearance Rate
• Models, Biological
• Niacin (blood)
• Rifamycins (blood)