title: Pharmacokinetic aspects of levofloxacin 500 mg once daily during sequential intravenous/oral therapy in patients with lower respiratory tract infections.
abstract: Levofloxacin is considered an effective antibiotic in the treatment of community-acquired lower respiratory tract infections (LRTIs). A study was carried out on 17 in-patients to assess the pharmacokinetics of a 500 mg once-daily switch intravenous (i.v.)/oral regimen of levofloxacin in the treatment of LRTI patients. Blood samples were collected under steady-state conditions at appropriate intervals. Levofloxacin plasma concentrations were analysed by means of HPLC and pharmacokinetic parameters were estimated using the WinNonlin pharmacokinetic software package. A lower clearance of levofloxacin (<2 mL/min/kg), conditioning both a longer elimination half-life (approximately 9 h) and a larger AUC(0-tau) (approximately 80 mg/L x h), was observed for both routes in our patients than in healthy volunteers. These differences may be explained considering that levofloxacin is excreted mainly as unchanged drug by the renal route, and most of our patients (71%) were very elderly subjects whose renal function physiologically declines with age. The almost complete (> or =99%) absolute oral bioavailability suggests that a comparable exposure to the iv regimen may be achieved after oral administration. The overall clinical success rate was 94.1%.
authors.affiliation: Institute of Clinical Pharmacology and Toxicology, Department of Experimental and Clinical Pathology and Medicine, Medical School, University of Udine, Ple S Maria della Misericordia 3, 33100 Udine, Italy.
authors.forename: Mario
authors.initials: M
authors.lastname: Furlanut
authors.forename: Loris
authors.initials: L
authors.lastname: Brollo
authors.forename: Emilio
authors.initials: E
authors.lastname: Lugatti
authors.forename: Elena
authors.initials: E
authors.lastname: Di Qual
authors.forename: Flavio
authors.initials: F
authors.lastname: Dolcet
authors.forename: Giovanni
authors.initials: G
authors.lastname: Talmassons
authors.forename: Federico
authors.initials: F
authors.lastname: Pea
mesh_terms: D000284:Administration, Oral; D000368:Aged; D000369:Aged, 80 and over; D019540:Area Under Curve; D015331:Cohort Studies; D004334:Drug Administration Schedule; D005260:Female; D006801:Humans; D007262:Infusions, Intravenous; D064704:Levofloxacin; D008297:Male; D008657:Metabolic Clearance Rate / Q000187:drug effects / Q000502:physiology; D008875:Middle Aged; D015242:Ofloxacin / Q000008:administration & dosage* / Q000493:pharmacokinetics*; D012141:Respiratory Tract Infections / Q000097:blood / Q000188:drug therapy* / Q000378:metabolism*; D018709:Statistics, Nonparametric
chemical_list: D064704:Levofloxacin; D015242:Ofloxacin