What is the recommended dosage of Fer-in-sol (iron supplement) for an 11-month-old, 8kg female patient?

Fer-in-Sol Dosage for 11-Month-Old, 8 kg Female

For an 11-month-old infant weighing 8 kg, administer 1 mg/kg/day of elemental iron, which equals 8 mg of elemental iron daily, or approximately 0.5 mL of Fer-in-Sol (15 mg iron/mL) oral drops once daily.

Recommended Dosing Strategy

Standard Prophylactic/Supplemental Dose

• The CDC recommends 1 mg/kg per day of elemental iron for exclusively or predominantly breastfed infants starting around 6 months of age 1
• For this 8 kg infant, this translates to 8 mg elemental iron daily
• With Fer-in-Sol at 15 mg/mL concentration, this equals approximately 0.5 mL once daily 1

Therapeutic Dose for Iron Deficiency Anemia

• If treating confirmed iron deficiency anemia (not just supplementation), the therapeutic dose is 3 mg/kg/day of elemental iron 2
• For this 8 kg infant, therapeutic dosing would be 24 mg elemental iron daily, or approximately 1.6 mL of Fer-in-Sol 2
• This higher dose should only be used when iron deficiency anemia is documented by laboratory testing 2

Optimal Administration Timing

Maximize Absorption

• Administer in the morning on an empty stomach (ideally 1 hour before or 2 hours after feeding) for optimal absorption 3
• If tolerated, give with a small amount of vitamin C-rich juice (like orange juice) to enhance absorption 3
• Avoid administering with milk, formula, tea, or calcium-containing foods/supplements, as these significantly impair iron absorption 3

If Gastrointestinal Side Effects Occur

• If the infant experiences constipation or other GI symptoms, consider giving with food to improve tolerance, though this reduces absorption 3
• Alternate-day dosing may improve fractional absorption and reduce side effects, though this strategy is better studied in older children and adults 4

Duration and Monitoring

Treatment Length

• For prophylactic supplementation: continue until the infant is consuming adequate iron from iron-fortified foods 1
• For therapeutic treatment of iron deficiency anemia: continue for 12 weeks minimum, then reassess hemoglobin and iron parameters 2

Expected Response

• With therapeutic dosing (3 mg/kg/day), expect hemoglobin to increase by approximately 4 g/dL over 12 weeks 2
• Monitor for resolution of anemia and repletion of iron stores (ferritin >15 ng/mL) 2

Critical Safety Considerations

Formulation Matters

• Ferrous sulfate (like Fer-in-Sol) is the preferred formulation as it provides 4-10 times better bioavailability than ferric iron preparations 5
• Low-dose ferrous sulfate once daily is more effective than iron polysaccharide complex 2

Common Pitfalls to Avoid

• Never exceed 3 mg/kg/day for routine supplementation without documented iron deficiency anemia 1, 2
• Ensure the infant remains upright for 30-60 minutes after administration to reduce risk of esophageal irritation 3
• Do not administer with antacids or proton pump inhibitors if the infant is on such medications, as these dramatically reduce absorption 3

When to Escalate Care

• If no improvement in hemoglobin after 4-6 weeks of therapeutic dosing, consider malabsorption, ongoing blood loss, or incorrect diagnosis 2
• Parenteral iron should be reserved for cases of documented oral iron failure, malabsorption, or intolerance 6