Effect of Antacid Medication on the Pharmacokinetics of Temafloxacin

Summary

The effect of an antacid drug (Maalox 70®) on the pharmacokinetics of temafloxacin was studied in 12 healthy young volunteers. The study was designed as a randomised open 2-period crossover trial in which temafloxacin was administered alone and with Maalox 70®. In both treatments, temafloxacin was administered as a single oral 400mg dose on the morning of day 2. In the antacid regimen, 8 doses of Maalox 70® were administered every 2h on day 1, starting at 8am and ending with the last dose at 10pm; 5 doses were given on day 2, at 2.5 and 1h before administration of temafloxacin and 1, 3 and 5h after the temafloxacin dose. With coadministration of Maalox 70®, peak plasma temafloxacin concentrations (C_max) were reduced to 44.6% (± 24.5), and AUC_(0–∞) was reduced to 39.8% (± 17.4) of the corresponding values obtained when temafloxacin was given alone. Urinary excretion of temafloxacin was reduced to 46.0% (± 13.7) of that observed when temafloxacin was administered alone. Time to peak plasma concentration (t_max = 1.8h) was not affected by antacid administration. Comparable or greater antacid-associated reductions in relative bioavailability have been reported for other quinolones. As with other quinolones, the concurrent administration of temafloxacin and antacids should be avoided.