indication

Magnesium hydroxide is used as a laxative to relieve occasional constipation (irregularity) and as an antacid to relieve indigestion, sour stomach, and heartburn.

mechanism of action

The term "Milk of Magnesia" was first used to describe a white aqueous, mildly alkaline suspension of magnesium hydroxide formulated at about 8%w/v. Milk of magnesia is primarily used to alleviate constipation, but can also be used to relieve indigestion and heartburn. When taken internally by mouth as a laxative, the osmotic force of the magnesia suspension acts to draw fluids from the body and to retain those already within the lumen of the intestine, serving to distend the bowel, thus stimulating nerves within the colon wall, inducing peristalsis and resulting in evacuation of colonic contents. Magnesium supplements have also been shown to reduce platelet aggregation by inhibiting in the influx of calcium, a crucial component of platelet aggregation.

drug interactions

Amprenavir: The antiacid decreases the absorption of amprenavir

Atazanavir: This gastric pH modifier decreases the levels/effects of atazanavir

Chloroquine: The antiacid decreases the absorption of chloroquine

Ciprofloxacin: Formation of non-absorbable complexes

Clodronate: Formation of non-absorbable complexes

Dapsone: Formation of non-absorbable complexes

Delavirdine: The antiacid decreases the effect of delavirdine

Demeclocycline: Formation of non-absorbable complexes

Doxycycline: Formation of non-absorbable complexes

Etidronic acid: Formation of non-absorbable complexes

Fosamprenavir: The antiacid decreases the absorption of amprenavir

Gatifloxacin: Formation of non-absorbable complexes

Gemifloxacin: Formation of non-absorbable complexes

Grepafloxacin: Formation of non-absorbable complexes

Ibandronate: Formation of non absorbable complexes

Indinavir: The antacid decreases the absorption of indinavir

Itraconazole: The antacid, magnesium oxide, may decrease the effect of itraconazole by decreasing its absorption.

Ketoconazole: The antacid, magnesium oxide, may decrease the effect of ketoconazole by decreasing its absorption.

Levofloxacin: Formation of non-absorbable complexes

Minocycline: Formation of non-absorbable complexes

Moxifloxacin: Formation of non-absorbable complexes

Norfloxacin: Formation of non-absorbable complexes

Ofloxacin: Formation of non-absorbable complexes

Tiludronate: The divalent cation of oral Magnesium oxide may significantly decrease the absorption of Tiludronate by forming a nonabsorbable chelate. Oral dosing should be separated by at least 2 hours.

Trovafloxacin: Magnesium may decrease the absorption of orally administered Trovafloxacin. Administer Trovafloxacin 2 hours before or 6 hours after a dose of the magnesium containing agent to minimize the interaction.