The effects of age and gender on the pharmacokinetics of irbesartan

Aims Single dose pharmacokinetics and safety of irbesartan, an angiotensin II receptor antagonist, were evaluated in healthy young and elderly male an d female subjects. Methods Irbesartan was administered as two 25 mg capsules after a 10 h fast to 12 young men, 12 young women, 12 elderly men and 12 elderly women. Seri al blood and urine sample were collected up to 96 h after the dose. Plasma and urine samples were analysed for irbesartan by h.p.l.c./fluorescence met hods. Results No statistically significant gender effects were observed in peak p lasma concentration (C-max), area under the curve (AUC), and terminal elimi nation half-life (t(1/2)) of irbesartan. The geometric mean AUC and C-max i ncreased by about 43% and 49%, respectively, in the elderly subjects. Also the time to peak was significantly shorter in the elderly subjects compared with that observed in the young subjects. Renal clearance of irbesartan wa s significantly reduced in the elderly females but this reduction is not li kely to be of any clinical relevance since less than 3% of the administered dose of irbesartan is excreted unchanged in the urine. Conclusions Although there was an effect of age on the pharmacokinetics of irbesartan, based on the safety and efficacy profile, no adjustment in irbe sartan dosage is necessary with respect to age or gender.