Zinc Dosing for Pediatric Diarrhea
For children with acute diarrhea, give 20 mg of elemental zinc daily for 10-14 days if the child is 6 months to 5 years old, or 10 mg daily for 10-14 days if under 6 months of age. 1, 2, 3
Age-Specific Dosing Algorithm
Children 6 Months to 5 Years
- Administer 20 mg elemental zinc daily for 10-14 days 1, 2, 3
- This dose reduces diarrhea duration by approximately 10-27 hours 1, 2
- The World Health Organization, American Academy of Pediatrics, and Infectious Diseases Society of America all support this dosing regimen 1, 2, 3
Infants Under 6 Months
- Administer 10 mg elemental zinc daily for 10-14 days 1, 4
- The American Academy of Pediatrics and World Health Organization recommend this lower dose specifically for younger infants 1
- Note that subgroup analyses show minimal benefit in children under 6 months, but the recommendation stands for zinc-deficient populations 5
Critical Implementation Details
When to Use Zinc Supplementation
- Strongly indicated in countries with high zinc deficiency prevalence 1, 2, 3
- Strongly indicated in children with signs of malnutrition or stunted growth 1, 2, 3
- Start within 3 days of diarrhea onset for maximum benefit (39% reduction in episodes lasting >7 days) 3
Duration of Treatment
- Continue the full 10-14 day course even if diarrhea resolves earlier 3
- This extended duration prevents recurrence over the subsequent 2-3 months 4
Important Caveats and Pitfalls
Vomiting Risk
- The standard 20 mg dose causes vomiting within 30 minutes in 19.3% of children 6
- Recent evidence shows 10 mg (15.6% vomiting) or 5 mg (13.7% vomiting) doses are noninferior for efficacy while causing significantly less vomiting 6
- However, current guidelines have not yet incorporated these lower doses, so the 20 mg dose remains the official recommendation 1, 2, 3
Never Substitute for Rehydration
- Oral rehydration therapy remains the cornerstone of diarrhea management 1, 2, 3
- Zinc is adjunctive therapy only 3
- Administer 50-100 mL/kg ORS over 2-4 hours depending on dehydration severity 2
- Replace each watery stool with 10 mL/kg of ORS 2
Contraindications to Avoid
- Never use antimotility drugs (loperamide) in children under 18 years due to risk of respiratory depression 2
- Do not restrict diet or prolong fasting, as this worsens nutritional status 2
- Continue breastfeeding throughout the diarrheal episode 2
Evidence Quality Considerations
The guideline recommendations are based on moderate-quality evidence showing zinc reduces the risk of continued diarrhea by 23% overall 3. The Cochrane review of 18 trials (6165 children) demonstrated zinc shortened diarrhea duration by 12.27 hours and reduced diarrhea persistence at days 3,5, and 7 5. For persistent diarrhea specifically, zinc reduced duration by 15.84 hours 5.