Effect of antacid medication on the pharmacokinetics of temafloxacin.

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 (Cmax) were reduced to 44.6% (+/- 24.5), and AUC(0-infinity) 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 (tmax = 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.