These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Metabolism of phenylbutazone in man.
    Author: Dieterle W, Faigle JW, Früh F, Mory H, Theoblad W, Alt KO, Richter WJ.
    Journal: Arzneimittelforschung; 1976 Apr; 26(4):572-7. PubMed ID: 782467.
    Abstract:
    One male volunteer received a single oral dose of 400 mg of 14C-labelled phenylbutazone (Butazolidin) and a second volunteer a repeated oral dose of 3 X 400 mg. The absorption from the gastro-intestinal tract was found to be rapid and complete. The integrated concentration of unchanged phenylbutazone in plasma, as estimated from the area under the concentration curve (AUC) between 0 and 336 h, was 63% of that of total 14C-substances. The corresponding AUC of three specifically determined metabolites, i.e. oxyphenbutazone, gamma-hydroxyphenylbutazone and p,gamma-dihydroxyphenylbutazone were 23%, 2% and 0.5%, respectively. A single oral dose was slowly excreted from the organism, since within 21 days only 88% was recovered, 61% from urine and 27% from faeces. About 1% of total urinary radioactivity was excreted as unchanged drug. The sum of specifically measured metabolites (oxyphenbutazone, gamma-hydroxyphenylbutazone, p,gamma-dihydroxyphenylbutazone) and phenylbutazone in urine did not cover more than about 10%. Solely oxyphenbutazone was present as an O-glucuronide, but only in small amounts. About 40% and 12% of total urinary radioactivity was due to C(4)-glucuronides of phenylbutazone and gamma-hydroxyphenylbutazone, respectively. Their structures were established by spectroscopic means. These metabolites contain pyrazolidine rings directly attached to glucuronic acid via a C-C bond, thus representing a novel class of drug metabolites.
    [Abstract] [Full Text] [Related] [New Search]