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Predicate | Object |
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rdf:type | |
lifeskim:mentions | |
pubmed:issue |
2
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pubmed:dateCreated |
1992-8-6
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pubmed:abstractText |
The disposition of [14C]finasteride, a competitive inhibitor of steroid 5 alpha-reductase, was investigated after oral administration of 38.1 mg (18.4 microCi) of drug in six healthy volunteers. Plasma, urine, and feces were collected for 7 days and assayed for total radioactivity. Concentrations of finasteride and its neutral metabolite, omega-hydroxyfinasteride (monohydroxylated on the t-butyl side chain), in plasma and urine were determined by HPLC assay. Mean excretion of radioactivity equivalents in urine and feces equaled 39.1 +/- 4.7% and 56.8 +/- 5.0% of the dose, respectively. The mean peak plasma concentrations reached for total radioactivity (ng equivalents), finasteride, and omega-hydroxyfinasteride were 596.5 +/- 88.3, 313.8 +/- 99.4, and 73.7 +/- 11.8 ng/ml, respectively, at approximately 2 hr; the mean terminal half-life for drug and metabolite was 5.9 +/- 1.3 and 8.4 +/- 1.7 hr, respectively. Of the 24-hr plasma radioactivity, 40.9% was finasteride, 11.8% was the neutral metabolite, and 26.7% was characterized as an acidic fraction of radioactivity. Binding of [14C]finasteride to plasma protein was extensive (91.3 to 89.8%), with a trend suggesting concentration dependency (range 0.02 to 2 micrograms/ml). Little of the dose was excreted in urine as parent (0.04%) or omega-hydroxyfinasteride (0.4%). Urinary excretion of radioactivity was largely in the form of acidic metabolite(s)--18.4 +/- 1.7% of the dose was eliminated as the omega-monocarboxylic acid metabolite. Finasteride was scarcely excreted unchanged in feces. In humans, finasteride is extensively metabolized through oxidative pathways.(ABSTRACT TRUNCATED AT 250 WORDS)
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pubmed:language |
eng
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pubmed:journal | |
pubmed:citationSubset |
IM
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pubmed:chemical |
http://linkedlifedata.com/resource/pubmed/chemical/Androstenes,
http://linkedlifedata.com/resource/pubmed/chemical/Azasteroids,
http://linkedlifedata.com/resource/pubmed/chemical/Carbon Radioisotopes,
http://linkedlifedata.com/resource/pubmed/chemical/Dihydrotestosterone,
http://linkedlifedata.com/resource/pubmed/chemical/Finasteride,
http://linkedlifedata.com/resource/pubmed/chemical/Testosterone
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pubmed:status |
MEDLINE
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pubmed:issn |
0090-9556
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pubmed:author | |
pubmed:issnType |
Print
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pubmed:volume |
20
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
148-55
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pubmed:dateRevised |
2004-11-17
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pubmed:meshHeading |
pubmed-meshheading:1352203-Administration, Oral,
pubmed-meshheading:1352203-Adult,
pubmed-meshheading:1352203-Androstenes,
pubmed-meshheading:1352203-Azasteroids,
pubmed-meshheading:1352203-Carbon Radioisotopes,
pubmed-meshheading:1352203-Dihydrotestosterone,
pubmed-meshheading:1352203-Feces,
pubmed-meshheading:1352203-Finasteride,
pubmed-meshheading:1352203-Humans,
pubmed-meshheading:1352203-Male,
pubmed-meshheading:1352203-Middle Aged,
pubmed-meshheading:1352203-Testosterone
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pubmed:articleTitle |
Disposition and pharmacokinetics of [14C]finasteride after oral administration in humans.
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pubmed:affiliation |
Department of Animal and Exploratory Drug Metabolism, Merck Sharp & Dohme Research Laboratories, Rahway, NJ 07065.
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pubmed:publicationType |
Journal Article
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