
Mechanism of effect
Aluminum hydroxide is a basic inorganic salt that acts by neutralizing hydrochloric acid in gastric secretions. Aluminum hydroxide is slowly solubilized in the stomach and reacts with hydrochloric acid to form aluminum chloride and water. It also inhibits the action of pepsin by increasing the pH and via adsorption. Cytoprotective effects may occur through increases in bicarbonate ion (HCO3-) and prostaglandins.
ءagnesium hydroxide will act by simple acid neutralization in the stomach. The hydroxide ions from the magnesium hydroxide will combine with the acidic H+ ions of the hydrochloric acid made by the stomachs parietal cells. This neutralization reaction will result in the formation of magnesium chloride and water.
Pharmacodynamic
Gastric-peptic disease occurs as a result of an imbalance between protective factors, such as mucus, bicarbonate, and prostaglandin secretion, and aggressive factors, such as hydrochloric acid, pepsin, and Helicobacter pylori (H. pylori). Antacids work by restoring acid-base balance, attenuating the pepsin activity and increasing bicarbonate and prostaglandin secretion.
magnesium hydroxide neutralizes gastric acid by reacting with hydrochloric acid in the stomach to form magnesium chloride and water. It is practically insoluble in water and does not have any effect until it reacts with the hydrochloric acid in the stomach. There, it decreases the direct acid irritant effect and increases the pH in the stomach leading to inactivation of pepsin. Magnesium hydroxide enhances the integrity of the mucosal barrier of the stomach as well as improving the tone of both the gastric and esophageal sphincters.
Pharmacokinetics
Duration
Fasting: 20-60 min
1 hr pc: up to 3 hr
Excretion
Aluminium oxide: absorbed Al ions are eliminated in the urine (0.1-0.5 mg of Al in aluminium-containing antacid is absorbed from standard daily doses of antacid), insoluble or poorly absorbed Al salts in the intestines are excreted in the feces
Magnesium oxide: absorbed Mg ions (up to 30%) are eliminated in urine, unabsorbed drug is excreted in feces
Drug indications
dyspepsiaDosage
Adult
Gastric Hyperacidity, Heartburn
10-20 mL PO between meals & qHS
Pediatric
Gastric Hyperacidity, Heartburn
< 12 years old: Safety & efficacy not established
> 12 years old: 10-20 mL PO between meals & qHS
Drug contraindications
excessive sensitivity to the drug or its componentInteractions
Ofloxacin , Tetracycline , Gemifloxacin , Dapsone , Doxycycline , Digoxin , Delavirdine , Pazopanib , raltegravir , Potassium Phosphate , Nitrendipine , baloxavir marboxil , Ponatinib , Fleroxacin , Oxytetracycline , Demeclocycline , Eltrombopag , Nisoldipine , Ciprofloxacin , Minocycline , Moxifloxacin , Nimodipine , Ketoconazole , IndinavirAlerts
Renal failure, Mg-restricted diet
May increase or decrease rate &/or degree of absorption of concomitantly administered oral drugs by changing GI transit time or by binding the drugPoints of recommendation
- Tell all of your health care providers that you take this medicine (aluminum hydroxide and magnesium hydroxide chewable tablets). This includes your doctors, nurses, pharmacists, and dentists.
- If you are on a low-magnesium diet, talk with your doctor.
- Do not take this medicine (aluminum hydroxide and magnesium hydroxide chewable tablets) for longer than you were told by your doctor.
- This medicine may prevent other drugs taken by mouth from getting into the body. If you take other drugs by mouth, you may need to take them at some other time than this medicine (aluminum hydroxide and magnesium hydroxide chewable tablets). Talk with your doctor.
- If you have phenylketonuria (PKU), talk with your doctor. Some products have phenylalanine.
- Do not give to a child younger than 12 years of age.
- Tell your doctor if you are pregnant or plan on getting pregnant. You will need to talk about the benefits and risks of using this medicine (aluminum hydroxide and magnesium hydroxide chewable tablets) while you are pregnant.
- Tell your doctor if you are breast-feeding. You will need to talk about any risks to your baby.
- Chew well or let dissolve in the mouth.
- If you take this medicine (aluminum hydroxide and magnesium hydroxide chewable tablets) on a regular basis, take a missed dose as soon as you think about it.
- If it is close to the time for your next dose, skip the missed dose and go back to your normal time.
- Do not take 2 doses at the same time or extra doses.
- Many times this medicine (aluminum hydroxide and magnesium hydroxide chewable tablets) is taken on an as needed basis. Do not take more often than told by the doctor.
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