Effect of aluminum hydroxide, an antacid, on the pharmacokinetics of new quinolones in humans.

Abstract

Effect of aluminum hydroxide on the pharmacokinetics of new quinolones, ofloxacin, enoxacin and norfloxacin, was investigated in cross-over study using five healthy male volunteers. Serum levels of the three drugs were decreased significantly up to 10 hours later by the concurrent administration of aluminum hydroxide. Cmax and AUC of the respective drug were decreased significantly by combined administration with aluminum hydroxide. Urinary excretion rates of the drugs within 24 hours were also decreased significantly by the concurrent administration of aluminum hydroxide. This combination effect of aluminum hydroxide on the pharmacokinetics of new quinolones was largest in case of norfloxacin and smallest in ofloxacin. Thus, these results suggest that the combination effect of aluminum hydroxide may be induced by the inhibition of absorption of new quinolones in the gastrointestinal tract.