Urinary Diazepam Metabolite Distribution in a Chronic Pain Population

作者：Luk Samantha; Atayee Rabia S; Ma Joseph D; Best Brookie M^*

来源：Journal of Analytical Toxicology, 2014, 38(3): 135-142.

DOI：10.1093/jat/bku001

Diazepam is often used as an adjuvant to pain therapy. Cytochrome P450 (CYP) 3A4 and 2C19 metabolize diazepam into the active metabolites: nordiazepam, temazepam and oxazepam. Owing to diazepams side-effect profile, mortality risk and potential for drugdrug interactions with CYP 3A4 and/or CYP 2C19 inhibitors, urine drug testing (UDT) could be a helpful monitoring tool. This was a retrospective data analysis that evaluated urine specimens from pain management practices for the distribution of diazepam metabolites with and without CYP 3A4 and 2C19 inhibitors. Intersubject nordiazepam, temazepam and oxazepam geometric mean fractions were 0.16, 0.34 and 0.47, respectively. Intrasubject geometric mean fractions were 0.157, 0.311 and 0.494, respectively. Sex, but not age or urinary pH, had an effect on metabolite fractions. Methadone significantly increased temazepam and oxazepam urinary fractions via CYP3A4 inhibition, whereas fluoxetine and esomeprazole increased nordiazepam fractions via CYP2C19 inhibition. Although more studies are needed, these results suggest the viability of UDT for increased monitoring for therapy and possible drugdrug interactions.

• 出版日期2014-4