title: Pharmacokinetics of ciprofloxacin in the elderly: increased oral bioavailability and reduced renal clearance.
abstract: The pharmacokinetics of ciprofloxacin was studied after single intravenous and oral doses of 250 mg and during and after a five-day oral regimen of 500 mg twice daily in eight young (22-34 years) and eight elderly (63-76 years), healthy male volunteers. The absolute bioavailability of an oral dose was greater in the elderly than in the young subjects at both 250 mg (72 versus 58%; p less than 0.05) and 500 mg (79 versus 63%; p less than 0.05). Distribution was unaffected by age. The physiological aging of the kidneys resulted in a reduced renal clearance, while no significant changes in non-renal clearance, total clearance and terminal half-life were found in the elderly. The age-related increase in the bioavailability of ciprofloxacin, whether due to facilitated absorption and/or reduced first-pass elimination, is a hitherto unique finding for antibiotics. As a consequence, reduction of orally administered doses of ciprofloxacin should be considered for elderly patients.
authors.affiliation: Department of Infectious Diseases, University Hospital, Lund, Sweden.
authors.forename: B
authors.initials: B
authors.lastname: Ljungberg
authors.forename: I
authors.initials: I
authors.lastname: Nilsson-Ehle
mesh_terms: D000284:Administration, Oral; D000328:Adult; D000368:Aged; D000375:Aging / Q000378:metabolism*; D001682:Biological Availability; D002939:Ciprofloxacin / Q000008:administration & dosage / Q000493:pharmacokinetics*; D006207:Half-Life; D006801:Humans; D007668:Kidney / Q000378:metabolism; D008297:Male; D008657:Metabolic Clearance Rate; D008875:Middle Aged
chemical_list: D002939:Ciprofloxacin