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Kinetics of biliary elimination of pentacaine in rats
Author(s) -
Bezek Š.,
Ščasnár V.,
Kukan M.,
Trnovec T.
Publication year - 1990
Publication title -
biopharmaceutics and drug disposition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.419
H-Index - 58
eISSN - 1099-081X
pISSN - 0142-2782
DOI - 10.1002/bdd.2510110505
Subject(s) - urine , feces , metabolite , excretion , medicine , chemistry , endocrinology , pharmacokinetics , metabolism , pharmacology , biology , paleontology
Pentacaine, a local anaesthetic of the carbanilate type, administered intravenously as 3 H‐pentacaine, 2mg kg −1 to rats, was eliminated in the bile mainly in the form of metabolites (20·5 ± 1·5 per cent of the dose) and as parent drug (0·1 per cent of the dose) within 3 days. In control rats 32·2 ± 2·5 and 37·8 ± 2·5 per cent of 3 H‐dose, representing pentacaine metabolites, were excreted in the urine and faeces, respectively. In bile‐ductucannulated rats 35·7 ± 6·8, 11·2 ± 3·4, and 20·5 ± 1·5 percent of 3 H‐dose were excreted in the urine, faeces, and bile, respectively. The high 3 H recovered in faeces in animals with diverted bile flow indicated passage of pentacaine metabolites through the intestinal wall. The excretion of pentacaine and its metabolites in bile was an active process, since the ratio bile/plasma concentration rapidly attained values approaching 10. In rats with ligated ureters the biliary elimination of pentacaine and its metabolites was enhanced, compensating for impaired urinary excretion. This was accompanied by increased plasma and brain levels of 3 H compared with untreated controls.