Pharmacokinetics of triazolam in geriatric patients

Serum triazolam levels were determined in eight geriatric patients (average age 80 years) on Days 1 and 7 of administration of triazolam 0.25 mg once daily, 1 h after a standard breakfast. Triazolam was rapidly absorbed reaching average peak concentrations of 2.0 and 2.04 ng/ml, 1.5 and 1.38 h after administration on Days 1 and 7, respectively. The mean apparent elimination half-life was 1.41 h (range 0.73-4.13 h) on Day 1 and 1.37 h (range 0.69-3.36 h) on Day 7. There was no significant difference between mean serum triazolam concentrations or pharmacokinetic parameters on Days 1 and 7 of the treatment. Serum samples were also assayed for alpha-hydroxytriazolam, an active metabolite of triazolam, but none could be detected in any of the samples from Days 1 or 7, assay sensitivity 0.09 ng/2 ml serum. The range of half-lives of triazolam in the patients in the present study is in close agreement with that previously reported in elderly subjects. The study provides further evidence of the lack of change in pharmacokinetic parameters on multiple dosing and that drug accumulation did not occur.