Urinary excretion profiles of two major triazolam metabolites, α-hydroxytriazolam and 4-hydroxytriazolam

Abstract

The objective of this study was to examine urinary excretion profiles of two major triazolam metabolites, α-hydroxytriazolam (α-OHTRZ) and 4-hydroxytriazolam (4-OHTRZ) in humans. Urine samples were collected from three healthy male volunteers who had been previously administered single 0.25- and 0.5-mg doses of triazolam 24 h and 48 h, respectively, before sample collection. After enzymatic hydrolysis and extraction, each sample was analyzed by liquid chromatography-mass spectrometry. α-OHTRZ was rapidly excreted, with the maximum concentrations appearing in the first or second sample collected after ingestion, with the majority of the drug being excreted within 12 h. Meanwhile, 4-OHTRZ was excreted more slowly than α-OHTRZ. The α-OHTRZ/4-OHTRZ ratios were initially greater than 19.7, then decreased rapidly, reaching a nearly constant value for times in excess of 12 h.