Magnesium hydroxide Diflunisal

Antacids containing aiuminium with or without magnesium can reduce the absorption of diflunisal by up to 40%, but no important interaction occurs if food is taken at the same time. Magnesium hydroxide can increase the rate of diflunisal absorption. 

Just how aluminium antacids reduce the absorption of diflunisal is not clear, but adsorption or formation of insoluble salts has been suggested. Food appears to diminish the effect of antacids on diflunisal absorption. By raising the pH, magnesium hydroxide may promote the dissolution of diflunisal, so increasing its absorption. Consider also NSAIDs Fena-mates + Antacids , below. 

Aluminium-containing antacids appear to reduce the absorption of diflunisal in the fasted state, but not if taken with food. Since NSAIDs should be taken with or after food, if appears that this interaction has little clinical relevance. See also NSAIDs Miscellaneous -I-Antacids , p.l42. Magnesium hydroxide increases the absorption of diflunisal in the fasted state. 

Uncertain. It is suggested that magnesium hydroxide increases the solubility of acidic drugs such as the fenamates, possibly by forming a soluble salt and therefore enhancing their dissolution. In contrast, aluminium antacids may form insoluble salts of the drug. Note that food may reduce these effects, see NSAIDs Diflunisal + Antacids , above. 

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