Open AccessEffect of antacid on absorption of the quinolone lomefloxacin
Author(s) -
Jingoro Shimada,
Kohya Shiba,
Tsuyoshi Oguma,
Hideaki Miwa,
Y. Yoshimura,
Toru Nishikawa,
Y Okabayashi,
Toshiro Kitagawa,
Satoshi Yamamoto
Publication year - 1992
Publication title -
antimicrobial agents and chemotherapy
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.07
H-Index - 259
eISSN - 1070-6283
pISSN - 0066-4804
DOI - 10.1128/aac.36.6.1219
Subject(s) - antacid , lomefloxacin , chemistry , chelation , absorption (acoustics) , magnesium , norfloxacin , nuclear chemistry , inorganic chemistry , biochemistry , antibiotics , materials science , organic chemistry , ciprofloxacin , composite material
The effect of antacid on the absorption of lomefloxacin (LFLX) in humans was studied. When LFLX was orally administered concomitantly with aluminum- and magnesium-containing antacids under fasting conditions, its level in plasma decreased by one-half and its area under the concentration-time curve was reduced by 40% compared with the levels observed after treatment with LFLX alone. The urinary recovery value also decreased by 40%. No such effects were noted after coadministration of LFLX and a nonmetallic antacid. This study confirmed the existence of chelate complexes of LFLX with Al3+ and Mg2+ and examined the chelating strength. The stability constants of LFLX with Al3+ and Mg2+ were measured and compared with those of ofloxacin and norfloxacin; little difference was observed among them. LFLX was found to bind more strongly with Al3+ than with Mg2+. Further, the existence of chelate formation was proven by 13C-nuclear magnetic resonance spectroscopy. The decrease in the LFLX level in plasma in humans could be explained by a reduced absorption of the Al(3+)- and Mg(2+)-LFLX chelate complexes.