Comparative Metabolic Studies of Phenacetin and Structurally-related Compounds in the Rat

Publisher Website
Google Scholar
Abstract
A comparative study of the metabolism of [acetyl-14C]phenacetin, [acetyl-14C]methacetin, [acetyl-14C]paracetamol and [acetyl-14C]acetanilide is reported in the rat. The extent of N-deacetylation, evidenced by the measurement of respired 14CO2, varied, being greatest with acetanilide (25-31%) and least with paracetamil (6%). The major urinary metabolites in each case were N-acetyl-p-aminophenyl sulfate and N-acetyl-p-aminophenyl glucuronide; the relative proportions varied with the sex of the animals and as a result of extended dosage. The metabolism of [ethyl-14C]phenacetin and [ethyl-14C]phenetidine was investigated and the extent of O-dealkylation determined by measurement of respired 14CO2. The metabolic pathways of some related glycolanilides and oxanilic acids included N-deacylation, and in the glycolanilides, oxidation of the glycollic group.