Milk of Magnesia (MoM) is a widely available over-the-counter medication recognized for its dual actions as both a laxative and an antacid. It contains magnesium hydroxide as its active ingredient. Magnesium hydroxide works by different mechanisms depending on its intended use, offering relief for various digestive discomforts like occasional constipation or acid indigestion and heartburn.
How to Use Milk of Magnesia
When used for constipation, Milk of Magnesia acts as a saline laxative, drawing water into the intestines through osmosis. This influx of water softens stool and increases its volume, stimulating bowel movements. For adults and children 12 years and older, the typical dosage is 30 to 60 milliliters (mL) taken once daily, often at bedtime. Children aged 6 to 11 years generally take 15 to 30 mL daily; consult a doctor for children under 6.
Drink a full glass of water, about 8 ounces, with each dose of Milk of Magnesia to aid its effectiveness and prevent dehydration. A bowel movement typically occurs within 30 minutes to 6 hours after taking the medication. Shake the bottle well before use and utilize a proper measuring device to ensure accurate dosing.
For indigestion and heartburn, Milk of Magnesia functions as an antacid, neutralizing excess stomach acid. Adults can take 5 to 15 mL, repeating the dose up to four times daily as needed. The total amount should not exceed 60 mL within a 24-hour period. Children aged 6 to 11 years may take smaller doses, up to 30 mL in 24 hours.
When to Exercise Caution
While generally safe when used as directed, Milk of Magnesia can cause side effects. Common side effects include diarrhea, abdominal cramping, and nausea. More serious, though less frequent, side effects are severe nausea or vomiting, a slow heartbeat, lightheadedness, or the absence of a bowel movement after using it as a laxative.
Prolonged or excessive use of Milk of Magnesia can lead to electrolyte imbalances, known as hypermagnesemia. Symptoms include muscle weakness, confusion, and decreased reflexes. Individuals with kidney disease are at a significantly higher risk of developing hypermagnesemia because their kidneys may not efficiently remove magnesium from the body.
Milk of Magnesia should be avoided in certain medical conditions. These include severe abdominal pain, nausea, vomiting, or symptoms indicating appendicitis or a bowel obstruction. People with a sudden change in bowel habits lasting longer than 14 days should also consult a doctor before use.
This medication can interact with other drugs, potentially reducing their absorption or effectiveness. Examples include certain antibiotics like tetracyclines and quinolones, iron supplements, and some heart medications. Separate the administration of Milk of Magnesia from other medications by at least two to three hours.
Milk of Magnesia is intended for short-term relief. Do not use for more than 7 days for constipation or 14 days for other digestive issues without medical advice. If symptoms persist or worsen, or if unusual side effects occur, consult a healthcare provider. Pregnant or breastfeeding individuals should also seek medical guidance before using this product.