title: Preliminary study of the pharmacokinetics of oral amifloxacin in elderly subjects.
abstract: Amifloxacin pharmacokinetics after a single oral dose in healthy elderly subjects were determined. Five males and five females aged 65 to 79 years and having creatinine clearances of 39.3 to 87.2 ml/h per kg of body weight were given a 200-mg amifloxacin caplet following an overnight fast. Mean (standard deviation) pharmacokinetic parameters for amifloxacin were as follows: maximum observed concentration in plasma, 1.13 (0.48) and 1.95 (0.52) micrograms/ml; half-life, 5.37 (0.96) and 4.47 (0.87) h; total plasma clearance (unadjusted for fraction absorbed), 259 (53) and 199 (55) ml/h per kg; renal clearance, 113 (20) and 86 (26) ml/h per kg; Varea/F (Varea is volume of distribution; F is fraction absorbed), 2.05 (0.75) and 1.28 (0.39) liter/kg; and amifloxacin excreted in the urine, 42.5% (14.5%) and 42.8% (10.6%) for males and females, respectively. There were no statistically significant differences in pharmacokinetic parameters between sexes that could not be attributed to differences in body weight. Except for a modest 23% reduction in renal clearance and the suggestion of reduced bioavailability, mean values of pharmacokinetic parameters for elderly male subjects were similar to those previously determined for younger male volunteers. Therefore, a modification in amifloxacin dosage regimen based solely on age may not be necessary.
authors.affiliation: Sterling Research Group, Rensselaer, New York 12144.
authors.forename: R M
authors.initials: RM
authors.lastname: Stroshane
authors.forename: M H
authors.initials: MH
authors.lastname: Silverman
authors.forename: R
authors.initials: R
authors.lastname: Sauerschell
authors.forename: R R
authors.initials: RR
authors.lastname: Brown
authors.forename: A W
authors.initials: AW
authors.lastname: Boddy
authors.forename: J A
authors.initials: JA
authors.lastname: Cook
mesh_terms: D000328:Adult; D000368:Aged; D000890:Anti-Infective Agents / Q000097:blood / Q000493:pharmacokinetics* / Q000652:urine; D001682:Biological Availability; D002939:Ciprofloxacin / Q000031:analogs & derivatives* / Q000097:blood / Q000493:pharmacokinetics / Q000652:urine; D005260:Female; D024841:Fluoroquinolones; D006801:Humans; D008297:Male; D013056:Spectrophotometry, Ultraviolet
chemical_list: D000890:Anti-Infective Agents; D024841:Fluoroquinolones; D002939:Ciprofloxacin; C040691:amifloxacin