title: Single- and multiple-dose pharmacokinetics of linezolid and co-amoxiclav in healthy human volunteers.
abstract: In an open, randomized, two-period crossover study the pharmacokinetics of linezolid and co-amoxiclav were investigated after single- and multiple-dose administration in 12 healthy volunteers (six females and six males). Linezolid was given in tablets of 600 mg twice a day for 7 days and co-amoxiclav in tablets of 1000 mg (875 + 125 mg) once a day for 7 days. The wash-out period was 4 weeks between the administration of the two antibacterial agents. Blood and urine samples were collected on days 1 and 7 before and at different time points up to 24 h after medication. The concentrations of the antibiotics in serum and urine were measured by validated high-performance liquid chromatography methods. Linezolid exhibited a mean C(max) of 14.5 +/- 4.6 mg/L after T(max) of 47.5 +/- 20.1 min on day 1, with a significant increase to 24.0 +/- 6.9 mg/L on day 7 (P < 0.01). The AUD(tot) (total area under the data) revealed a significant increase from 140.5 +/- 28.3 mg.h/L on day 1 to 220.2 +/- 42.6 mg.h/L on day 7 (P < 0.01). There were no significant differences in terminal elimination half-life between days 1 and 7 (9.53 +/- 2.87 versus 7.97 +/- 3.08 h) or in total clearance (71.6 +/- 17.6 versus 81.5 +/- 14.7 ml/min.1.73 m(2)). Results are in agreement with the assumption of a limited accumulation of linezolid under the dosage regimen given. Serum linezolid concentrations in females were always higher than those in males. The volume of distribution V(ss)/f differed significantly between females and males (41.6 +/- 4.2 versus 52.2 +/- 3.3 L/70 kg; P < 0.01). Pharmacokinetic parameters of amoxicillin and clavulanic acid found in this study were similar to previously published data. No accumulation was found with co-amoxiclav. No serious adverse event was observed with the study drugs.
authors.affiliation: Department of Chest and Infectious Diseases, Chest Hospital Heckeshorn, affil Freie Universität Berlin, Zum Heckeshorn 33, D-14109 Berlin, Germany.
authors.forename: Olaf
authors.initials: O
authors.lastname: Burkhardt
authors.forename: Klaus
authors.initials: K
authors.lastname: Borner
authors.forename: Nicolas
authors.initials: N
authors.lastname: von der Höh
authors.forename: Peter
authors.initials: P
authors.lastname: Köppe
authors.forename: Mathias Wilhelm
authors.initials: MW
authors.lastname: Pletz
authors.forename: Carl Erik
authors.initials: CE
authors.lastname: Nord
authors.forename: Hartmut
authors.initials: H
authors.lastname: Lode
mesh_terms: D000081:Acetamides / Q000008:administration & dosage* / Q000097:blood / Q000493:pharmacokinetics*; D000328:Adult; D019980:Amoxicillin-Potassium Clavulanate Combination / Q000008:administration & dosage* / Q000097:blood / Q000493:pharmacokinetics*; D019540:Area Under Curve; D018592:Cross-Over Studies; D004334:Drug Administration Schedule; D005260:Female; D006801:Humans; D000069349:Linezolid; D008297:Male; D023303:Oxazolidinones / Q000008:administration & dosage* / Q000097:blood / Q000493:pharmacokinetics*; D012737:Sex Factors; D018709:Statistics, Nonparametric
chemical_list: D000081:Acetamides; D023303:Oxazolidinones; D019980:Amoxicillin-Potassium Clavulanate Combination; D000069349:Linezolid