Antacids Diflunisal

Drugs that may be affected by antacids include allopurinol, amphetamines, benzodiazepines, captopril, chloroquine, corticosteroids, dicumarol, diflunisal, digoxin, ethambutol, flecainide, fluoroquinolones, histamine H2 antagonists,... 

Diflunisal Overdose (15 g) of diflunisal leads to poisoning, which could be fatal.51 Treatment can be given by gastric lavage and supportive care. Interactions of diflunisal with indomethacin, paracetamol, antacids, benzodiazepines, and probenecid have been reported.5 Concomitant use with indomethacin should be avoided, as this could cause fatal GI complications. 

Tobert JA, DeSchepper P, Tjandramaga TB, Mullie A, Buntinx AP, Meisinger MAP, Huber PB, Hall TLP, Yeh KC. Effect of antacids on the bioavailability of diflunisal in the fasting and postprandial states. Clin Pharmacol Ther 30, 385-9. 

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. 

Not known. Aluminium compounds might form insoluble salts with indometacin. Food might reduce this effect, see NSAIDs Diflunisal + Antacids , p.l40. 

Although information is limited, no particular precautions would seem to be needed if aluminium or aluminium/magnesium antacids are given with any of these antacids. Note that antacids have been frequently given with NSAIDs to reduce their gastric irritant effects. Consider also coxibs , (p.l39), diclofenac , (p.l40), diflunisal ,(p.l40), ibuprofenand related drugs , (p.l40), indometacin , (p.l41), fenamates , (p.l40), and oxi-cams , (below) for information about the interaction of other NSAIDs with antacids. 

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