Single‐Dose Pharmacokinetics of Isepamicin in Young and Geriatric Volunteers

Isepamicin is a new aminoglycoside antibiotic with activity against both gram‐negative and gram‐positive bacteria. The pharmacokinetics of isepamicin were evaluated after a 0.5‐hour intravenous infusion of a 15‐mg/kg dose to groups of young adults and geriatric volunteers. Isepamicin was safe and well tolerated. No adverse events related to the infusion were reported. As age increased, there were increases in the elimination phase half‐life (t 1/2 β) and the area under the plasma concentration—time curve extrapolated to infinity (AUC 0‐∞ ), and decreases in systemic (Cl) and renal clearance (Clr). The changes seen in Cl with age were a result of changes in renal function estimated by creatinine clearance (Clcr). There were no apparent correlations between age and maximum plasma concentration (C max ), half‐life of the τ‐phase (t 1/2 τ), volume of distribution at steady‐state (Vdss), or the amount of isepamicin excreted in urine within 24 hours after dose administration (Ae 24 hrs ). When comparing the elderly (61–80 years old) with the younger (21–60 years) volunteers, the (AUC 0‐∞ ), and t 1/2 β values were higher in the elderly and the Cl and Clr values were lower, but C max , t 1/2 τ and Vdss were similar in the two age groups. The contribution of the τ‐phase to the overall AUC was minimal and similar for the two age groups. Also, there were no gender effects on the pharmacokinetics of isepamicin in both the young and elderly volunteers. These results demonstrate that changes in the pharmacokinetics of isepamicin in the elderly are attributable to changes in renal function, whereas age, per se, is not a significant factor.