Effect of quinolones on caffeine disposition |
| |
Authors: | M Carbó J Segura R De la Torre J M Badenas J Camí |
| |
Affiliation: | Department of Pharmacology and Toxicology, Institut Municipal d'Investigació Mèdica, Barcelona, Spain. |
| |
Abstract: | Six healthy volunteers received a single caffeine dose after pretreatment with norfloxacin, pipemidic acid, or placebo in a crossover, randomized, single-blind clinical trial. Quinolones altered the pharmacokinetics of caffeine, with a significant increase in the AUCs and a decrease in plasma clearance. The elimination half-life increased significantly with pipemidic acid. The apparent volume of distribution, mean renal clearance, and time to reach maximum caffeine concentrations remained unaltered. There was a decline in caffeine metabolite levels in the 24-hour urine samples for both quinolone treatments, suggesting that pipemidic acid and, to a lesser degree, norfloxacin inhibit metabolism of the N-demethylation pathways of caffeine. The practical consequence of this observation could be caffeine accumulation during repeated intake of coffee. In two additional healthy volunteers under a controlled multiple-dose regimen of caffeine ingestion, administration of pipemidic acid for 2 days caused a fourfold increase in the plasma concentrations of caffeine. |
| |
Keywords: | |
|
|