title: Lack of interaction between lomefloxacin and caffeine in normal volunteers.
abstract: Sixteen healthy, nonsmoking adult males participated in a randomized, double-blind, placebo-controlled, two-way crossover study to evaluate the influence of chronic lomefloxacin administration on the disposition of caffeine and its major metabolite, paraxanthine, at steady-state conditions. Lomefloxacin (400 mg) or placebo was administered orally once daily for 5 days to xanthine-free volunteers after an overnight fast. Caffeine (200 mg orally) was administered simultaneously with lomefloxacin on days 3 through 5. After a 2-day washout period, subjects were crossed over to the alternate 5-day regimen with caffeine, which was again given on the final 3 days. Blood samples for caffeine, paraxanthine, and lomefloxacin concentration determinations were serially collected for 48 h following the last dose of each regimen. All compounds were analyzed by high-performance liquid chromatography. For the placebo versus lomefloxacin-containing treatments, maximum caffeine concentrations in plasma (4.35 +/- 0.63 versus 4.07 +/- 0.56 micrograms/ml), areas under the concentration-time curve from time zero to 24 h at steady state (30.3 +/- 6.9 versus 29.7 +/- 6.6 micrograms.h/ml), and elimination half-lives of caffeine (4.8 +/- 1.1 versus 4.8 +/- 1.2 h) were not significantly different. In addition, there were no significant changes in the disposition parameters of paraxanthine as a result of lomefloxacin administration. The frequencies of central nervous system-related effects for the two treatments were not statistically different. We conclude that lomefloxacin has no significant effect on the disposition of caffeine in young healthy volunteers.
authors.affiliation: Department of Pharmacy and Pharmaceutics, School of Pharmacy, Medical College of Virginia/Virginia Commonwealth University, Richmond 23298-0581.
authors.forename: D P
authors.initials: DP
authors.lastname: Healy
authors.forename: J R
authors.initials: JR
authors.lastname: Schoenle
authors.forename: J
authors.initials: J
authors.lastname: Stotka
authors.forename: R E
authors.initials: RE
authors.lastname: Polk
mesh_terms: D042462:4-Quinolones; D000328:Adult; D000890:Anti-Infective Agents / Q000493:pharmacokinetics / Q000494:pharmacology*; D002110:Caffeine / Q000493:pharmacokinetics*; D004311:Double-Blind Method; D004347:Drug Interactions; D024841:Fluoroquinolones; D006207:Half-Life; D006801:Humans; D008297:Male; D015363:Quinolones; D013806:Theophylline / Q000493:pharmacokinetics
chemical_list: D042462:4-Quinolones; D000890:Anti-Infective Agents; D024841:Fluoroquinolones; D015363:Quinolones; D002110:Caffeine; D013806:Theophylline; C053091:lomefloxacin; C021183:1,7-dimethylxanthine