RELATIONSHIP BETWEEN SINGLE ORAL DOSE PHARMACOKINETICS OF ALPRAZOLAM AND TRIAZOLAM

The relationship between the single oral dose pharmacokinetics of alpr azolam and triazolam was studied in 10 healthy male volunteers. Each s ubject took single oral doses of alprazolam 0.8 mg and triazolam 0.5 m g with at least a 2 week interval between each dose. Blood samplings w ere performed up to 48 h after alprazolam dosing and up to 12 h after triazolam dosing. Plasma concentrations of both drugs were measured by high-performance liquid chromatography. The means +/- standard deviat ion of the peak plasma concentration, the total area under the plasma concentration-time curve and the elimination half-life of alprazolam w ere 11.3 +/- 3.1 ng/ml, 232.3 +/- 59.2 ng/h/ml and 16.5 +/- 4.6 h, res pectively, and those of triazolam were 3.2 +/- 1.0 ng/ml, 11.8 +/- 5.2 ng/h/ml and 2.5 +/- 1.1 h, respectively. There was no significant cor relation between the two drugs in any pharmacokinetic parameters (r = 0.35, 0.25 and 0.50). The present study thus suggests that the single oral dose pharmacokinetics of alprazolam and triazolam do not correlat e well in individuals.