Pediatric Dosage of Milk of Magnesia (Magnesium Hydroxide)
The recommended dosage of milk of magnesia for pediatric patients is age-dependent: children 6-11 years should receive 1-2 chewable tablets or 15-30 mL, and children under 6 years should be dosed only under medical supervision. 1
Age-Based Dosing Guidelines
Milk of magnesia (magnesium hydroxide) is commonly used as a laxative for constipation in children. The appropriate dosage varies by age:
- Children under 6 years: Consult a doctor for appropriate dosing 1
- Children 6-11 years: 1-2 chewable tablets or 15-30 mL of liquid formulation
- Children 12 years and older: 2-4 chewable tablets or 30-60 mL of liquid formulation
Administration Guidelines
- Give with a full glass (8 oz) of water or other liquid
- May be administered as a single daily dose or divided doses
- Do not exceed the maximum recommended daily dose in a 24-hour period
- For liquid formulations, use the measuring device provided with the medication
Efficacy and Safety Considerations
Recent research has shown that milk of magnesia is effective for treating constipation in children, with comparable efficacy to polyethylene glycol (PEG) in children from 6 months to 18 years of age 2. However, there are important safety considerations:
- Risk of hypermagnesemia: Even in children with normal renal function, excessive doses can cause hypermagnesemia, which may present with vomiting, decreased consciousness, and reduced muscle tone 3
- Acceptability issues: Children over 4 years of age tend to reject milk of magnesia more frequently than PEG, which may affect compliance 2
Alternative Treatment Options
If milk of magnesia is not tolerated or ineffective:
- Polyethylene glycol (PEG) has been shown to be equally effective as milk of magnesia with better acceptance in children over 4 years 2, 4
- In a 12-month study, compliance rates were 95% for PEG versus 65% for milk of magnesia 4
Monitoring and Precautions
- Monitor for signs of hypermagnesemia: drowsiness, muscle weakness, respiratory depression
- Ensure adequate hydration when administering
- Discontinue use and seek medical attention if adverse effects occur
- Avoid prolonged use without medical supervision
Special Populations
- Infants and young children: Milk of magnesia can be considered first-line treatment for functional constipation in children under 4 years of age 2
- Children with renal impairment: Use with extreme caution due to increased risk of magnesium toxicity
Remember that while milk of magnesia is generally safe when used as directed, careful attention to dosing is essential to prevent adverse effects, particularly in younger children.