title: Decrease of caffeine elimination in man during co-administration of 4-quinolones.
abstract: The single dose pharmacokinetics of caffeine (220-230 mg per dose) were investigated in 12 healthy male volunteers before and during treatment with ofloxacin (200 mg bd), ciprofloxacin (250 mg bd) and enoxacin (400 mg bd) with a cross-over study design. None of the parameters: mean elimination half-life (T1/2el), Cmax, total body clearance (Cltot) and the volume of distribution (aVd) of caffeine were noticeably altered by administration of ofloxacin. Striking changes were observed, however, after administration of enoxacin: the T1/2el was prolonged by as much as 260%, the Cmax increased by 41%; the aVd was reduced by 20% and Cltot by 78% (mean values). Treatment with ciprofloxacin led to a prolongation of T1/2el by 15%, to a decrease of aVd by 25% and to a 33% decrease of Cltot. The results of this intra-individual comparison of caffeine pharmacokinetic data demonstrate that treatment with ciprofloxacin and enoxacin may have a significant inhibitory effect on caffeine elimination.
mesh_terms: D000328:Adult; D000890:Anti-Infective Agents / Q000494:pharmacology; D002110:Caffeine / Q000097:blood / Q000493:pharmacokinetics*; D002851:Chromatography, High Pressure Liquid; D002939:Ciprofloxacin / Q000494:pharmacology; D004347:Drug Interactions; D015365:Enoxacin; D006207:Half-Life; D006801:Humans; D008297:Male; D009287:Naphthyridines / Q000494:pharmacology; D015242:Ofloxacin; D010078:Oxazines / Q000494:pharmacology; D011804:Quinolines / Q000494:pharmacology*
chemical_list: D000890:Anti-Infective Agents; D009287:Naphthyridines; D010078:Oxazines; D011804:Quinolines; D015365:Enoxacin; D002110:Caffeine; D002939:Ciprofloxacin; D015242:Ofloxacin