title: Absence of a pharmacokinetic interaction between intravenous theophylline and orally administered levofloxacin.
abstract: A randomized, placebo-controlled, two-way crossover study in 16 healthy men was performed to determine the effect of orally administered levofloxacin at steady-state conditions, given at 500 mg every 12 hours, on the pharmacokinetics of theophylline given as a single 4.5-mg/kg intravenous infusion. Participants were assigned randomly to receive theophylline with levofloxacin in one study period and theophylline with placebo in the other period. Fourteen individuals completed the study. Mean (+/-SD) values for theophylline pharmacokinetic parameters for the levofloxacin and placebo treatments, respectively, were peak plasma concentrations (Cmax) of 11.4 (1.8) micrograms/mL and 10.7 (1.3) micrograms/mL; areas under the concentration time curve from time 0 extrapolated to infinity (AUCzero-infinity) of 124 (32) micrograms.hr/mL and 126 (30) micrograms.hr/mL; volumes of distribution at steady state (Vdss) 31.7 (3.5) L and 32.0 (3.9) L; clearances (Cl) of 48.6 (11.6) mL/min and 47.4 (10.3) mL/min; and half-lives (t1/2) of 8.1 (1.9) hours and 8.2 (1.8) hours. There were no statistically significant differences between treatments for any of these parameters. There was no pharmacokinetic interaction between levofloxacin administered orally at steady-state conditions and intravenously administered theophylline.
authors.affiliation: R. W. Johnson Pharmaceutical Research Institute, Spring House, PA 19477, USA.
authors.forename: L G
authors.initials: LG
authors.lastname: Gisclon
authors.forename: C R
authors.initials: CR
authors.lastname: Curtin
authors.forename: C L
authors.initials: CL
authors.lastname: Fowler
authors.forename: R R
authors.initials: RR
authors.lastname: Williams
authors.forename: B
authors.initials: B
authors.lastname: Hafkin
authors.forename: J
authors.initials: J
authors.lastname: Natarajan
mesh_terms: D000328:Adult; D000890:Anti-Infective Agents / Q000008:administration & dosage / Q000493:pharmacokinetics*; D001993:Bronchodilator Agents / Q000008:administration & dosage / Q000493:pharmacokinetics*; D018592:Cross-Over Studies; D004311:Double-Blind Method; D006207:Half-Life; D006801:Humans; D007275:Injections, Intravenous; D064704:Levofloxacin; D008297:Male; D015242:Ofloxacin / Q000008:administration & dosage / Q000493:pharmacokinetics*; D013806:Theophylline / Q000008:administration & dosage / Q000493:pharmacokinetics*
chemical_list: D000890:Anti-Infective Agents; D001993:Bronchodilator Agents; D064704:Levofloxacin; D015242:Ofloxacin; D013806:Theophylline