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A [ 14 C]Phenacetin Breath Test to Measure Hepatic Function in Man
Author(s) -
Breen Kerry J.,
Bury Ross W.,
Calder Ian V.,
Desmond Paul V.,
Peters Marion,
Mashford M. Laurie
Publication year - 1984
Publication title -
hepatology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.488
H-Index - 361
eISSN - 1527-3350
pISSN - 0270-9139
DOI - 10.1002/hep.1840040108
Subject(s) - phenacetin , breath test , hepatic function , medicine , pharmacology , chemistry , gastroenterology , helicobacter pylori
Phenacetin, a high‐clearance drug, was labeled as [ 14 C‐ethyl]phenacetin and used in a breath test of hepatic function. 14 CO 2 appeared rapidly in breath such that more than 30% of the administered radioactivity was expired in 2 hr. For all means of expression used to describe the appearance of 14 CO 2 in breath, normal controls and hospitalized patients without liver disease were clearly separated from cirrhotic subjects with moderate and severe liver damage. The phenacetin breath test was validated by the close correlation of 14 CO 2 appearance with the disposition of the parent compound examined after its intravenous administration, and by demonstration that the rate‐limiting step in 14 CO 2 generation from labeled phenacetin occurred proximal to 14 CO 2 generation from [ 14 C]acetate given intravenously. Correcting for the actual volume of CO 2 exhaled by control and cirrhotic subjects did not increase the sensitivity of the test. The phenacetin breath test has potential as a simple procedure to quantitate hepatic metabolism of drugs, particularly those mediated by cytochrome P448.