Ferrous sulfate Aluminium hydroxide

Phenytoin, carbamazepine, phenobarbital, rifampin, rifabutin Iopanoic acid, ipodate, amiodarone, beta-blockers, corticosteroids, propylthiouracil, cholestyramine, colestipol, aluminium hydroxide, sucralfate, ferrous sulfate, some calcium preparations Interferon-c/, interleukin-2... 

Shiba K, Kus ima H, Momo K. The effects of aluminium hydroxide, dmetidine, ferrous sulfate, green tea and milk on pharmacokinetics of gatifloxacin in healthy humans. 

Uneertain. One suggestion is that magnesium sulfate changes ferrous sulfate into less easily absorbed salts, or increases its polymerisation. Carbonates possibly cause the formation of poorly soluble iron complexes. Aluminium hydroxide is believed to precipitate iron as the hydroxide and ferrie ions can become intercalated into the aluminium hydroxide crystal lattice, leaving less available for absorption. 

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