Pharmacokinetics of Aztreonam in Healthy Elderly and Young Adult Volunteers

Abstract

Aztreonam is a monobactam exhibiting an antibacterial spectrum similar to that of the aminoglycosides, with activity against aerobic gram-negative bacilli, and is the only related drug that may be given to patients hypersensitive to beta-lactams. The pharmacokinetics of aztreonam were compared in two groups of healthy volunteers. The young group comprised 10 adults between the ages of 18 and 30 years, and the elderly group included 10 adults older than 65 years of age. The two groups each received two doses (1 and 2 g) aztreonam, separated by 1 week. Although the mean peak serum concentrations of aztreonam for the two groups were similar, there were differences in other pharmacokinetic parameters. For example, for the 2-g dose the mean half-life (1.8 +/- .51 versus 3.1 +/- .9 hour), and area under the curve (AUC) (294.42 +/- 64.08 versus 469.01 +/- 144.02 micrograms x hour/mL per 1.73 m2) were less for the younger group compared with the elderly group. The mean total body clearance of aztreonam was greater for the younger than the elderly group. The results were similar to the pharmacokinetic parameters derived from the 1-g dose. These results mirror the lower creatinine clearances and higher serum creatinine levels found in the elderly group. The data suggest that lower doses of aztreonam given at less frequent intervals may be appropriate in the elderly population.

Adsorption and release of ampicillin antibiotic from ordered mesoporous silica

“…The maximal amount of released drug corresponds to an ampicillin concentration in the release solution of 327 g/mL, 210 g/mL, and 145 g/mL for MCM-41, SBA-15, and SBA-15-NH2, respectively. We observe that the latter value (SBA-15-NH2) is comparable to the concentration of ampicillin in the serum of both adults and children [50,51]. Similar release kinetics were reported for amoxicillin release from pure and functionalized SBA-15 and MCM-41 [25,41].…”

“…After the administration, the maximal concentration of ampicillin in blood serum mainly depends on the patient's age. For adults (from 20 to 65 years) who have been administered with 2 g of ampicillin, the maximal measured concentration is about 80-110 µg/mL [50]. While for children (from 1 to 12 years) a dose of 40-80 mg/kg every 6 h results in an ampicillin concentration of 177-200 µg/mL [51].…”

Adequate antimicrobial treatment in elderly patients

“…The pharmacokinetic studies show that most antimicrobial blood concentrations are different in elderly patients. The decline in kidney function is the most important and consistent pharmacokinetic change in elderly patients [73,[75][76][77][78][79][80][81][82][83][84][85][86][87]89]. However, a few studies did not find differences in antimicrobial clearance [69,70,74].…”

“…Monobactams. Meyers et al found higher aztreonam blood concentrations in elderly patients, due to decreased renal clearance [83]. The Vd of aztreonam was increased in elderly patients.…”