Glucuronide drug metabolism studies

Wainhaus, S.B., Acyl glucuronides Assays and issues, in Using Mass Spectrometry for Drug Metabolism Studies, W.A. Korfmacher, ed. 2005, CRC Press Boca Raton, FL. p. 175. 

Faed, E. M. (1984). Properties of acyl glucuronides. Implications for studies of the pharmacokinetics and metabolism of acidic drugs. Drug Metab. Rev. 15 1213-1249. 

Faed, E.M. Properties of Acyl Glucuronides Implications for Studies of the Pharmacokinetics and Metabolism of Acidic Drugs, Drug Metab. Dispos. 15, 1213-1249(1984). 

Age. The pharmacokinetic and pharmacodynamic effects of a drug can be influenced by age, and drug metabolism plays an important role in understanding the differences observed. Differences between the levels of metabolism enzymes for the fetal and neonatal (first 4 weeks postpartum) liver versus the adult liver have been observed in both animal and human studies (125). At birth, total CYP levels are approximately 30%of adult levels and glucuronidation activity is at 10-30% of adult levels. Interestingly, sulfotransferase activity in neonates seems to be comparable with that in adults. 

With namoxyrate, the acid moiety (IX) is strongly bound by plasma proteins. It deposits largely in fat and muscle and to a smaller extent in the brain.Contrary to expectations, the drug is not converted to a hydroxyl or glucuronide metabolite but excreted unchanged. The observed differences in distribution and metabolism of several aryl acetic acids indicate that comparative metabolic studies may be a practical approach to evaluate the long-term safety of many active aryl aliphatic acids. 

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