Ranitidine Magnesium hydroxide

The pharmacokinetics of a singie dose of metrifonate were not ai-tered by an antacid containing aiuminium/magnesium hydroxide, nor by pretreatment with cimetidine or ranitidine. 

Deppermann K-M, Lode H, HofQ en G, Tschink G, Kalz C, Koeppe P. Influence of ranitidine, pirenzepine, and aluminum magnesium hydroxide on the bioavailability of various antibiotics, including amoxicillin, cephalexin, doxycycline and amoxicillin-clavulanic acid. Antmdcrob Agents Chemodier( 9Z9) 33,1901-1907. 

Reductions of up to 59% were found in another study. Yet another study showed that aluminium phosphate redueed the bioavailability of ranitidine by 30%. In contrast, another study found no signifieant ehanges in the pharmacokinetics of ranitidine given with an aluminium/magnesium hydroxide antacid (Maalcxx). 

Mylanta II (aluminium/magnesium hydroxide mixture) 30 mL reduced the ranitidine peak serum levels and AUC after a single 150-mg dose by about one-third in 6 healthy subjects. Mylanta Double Strength (aluminium/magnesium hydroxide with simeticone) reduced the absorption of ranitidine by 26%, which was not thought to be clinically significant. ... 

Why are cimetidine and ranitidine better antacids than sodium hydrogencarbonate or magnesium or aluminium hydroxide ... 

Roxithromycin did not alter the pharmacokinetics of carbamazepine (15) or interact with warfarin, ranitidine, or antacids containing hydroxides of aluminium and magnesium (1). 

Hebiig R, Boettcher M, Herman-Gnjidic Z, Pierce CH. Effects of magnesium/aluminium hydroxide-containing antacid, cimeti( ne or ranitidine on the pharmacokinetics of metrifonate and its metabolite DDVP. Clin Drug Invest (1999) 17, 67-77,... 

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