Ferrous Sulfate Elixir Dosing (44 mg elemental iron per 5 mL)
For adults with iron deficiency anemia, administer 5-10 mL (44-88 mg elemental iron) once daily in the morning on an empty stomach, ideally with vitamin C; for children, use 2-6 mg/kg/day of elemental iron (approximately 0.2-0.7 mL/kg), not exceeding adult doses 1, 2.
Adult Dosing
The optimal approach is 50-100 mg elemental iron once daily, which translates to:
- 5-10 mL of your elixir (44-88 mg elemental iron) once daily 1
Timing and Administration
- Administer in the morning on an empty stomach for maximum absorption 3
- Add vitamin C (approximately 100 mg) or take with citrus juice to enhance absorption 4, 3
- If vitamin C unavailable, take with plain water—never with milk, tea, coffee, or food 3
- Patient should remain upright for 30-60 minutes after dosing to prevent pill/liquid esophagitis 3
Alternative Dosing Strategy
Every-other-day dosing may be equally effective with better tolerability 4, 5:
- Give 10-20 mL (88-176 mg elemental iron) every other day instead of daily dosing
- This approach increases fractional iron absorption by 40-50% compared to consecutive daily dosing 5
- Particularly useful for patients experiencing gastrointestinal side effects 1, 6
Pediatric Dosing
For children aged 6 months to 12 years: 2-6 mg/kg/day of elemental iron 7, 2, 8:
- Calculate: (Weight in kg × 2-6 mg) ÷ 44 mg per 5 mL = mL dose
- Example: 10 kg child = 20-60 mg elemental iron = approximately 2.3-6.8 mL daily
- Optimal dose appears to be 2-3 mg/kg/day based on recent evidence 7, 2
A 2020 study demonstrated that 2 mg/kg/day achieved 95% hemoglobin normalization and 84% ferritin normalization at 3 months in children aged 6-17 months 7. A 2017 trial showed 3 mg/kg/day of ferrous sulfate was superior to iron polysaccharide complex for treating pediatric iron deficiency anemia 2.
Monitoring and Duration
- Check hemoglobin at 2 weeks: An increase of <10 g/L predicts treatment failure (90% sensitivity) 1
- Monitor hemoglobin every 4 weeks until normalized 1
- Continue treatment for 2-3 months after hemoglobin normalization to replenish iron stores 1
Critical Caveats
Avoid these common errors:
- Do not dose twice daily—this increases hepcidin and reduces subsequent iron absorption by 35-45% 1
- Avoid modified-release preparations—they are less suitable for prescribing 1
- Do not co-administer with calcium supplements, antacids, H2 blockers, or proton pump inhibitors—these markedly reduce absorption 3
- Avoid afternoon dosing—absorption is significantly lower than morning administration 3
When to Switch to IV Iron
Consider intravenous iron if 4:
- Patient cannot tolerate oral iron despite alternate-day dosing
- Ferritin fails to improve after adequate oral trial
- Conditions impairing absorption (inflammatory bowel disease, post-bariatric surgery, celiac disease)
The evidence strongly supports ferrous sulfate as the preferred formulation due to superior efficacy and cost-effectiveness compared to other oral iron preparations 4, 2, 9. While gastrointestinal side effects occur in approximately 30-35% of patients 9, 6, alternate-day dosing reduces these by approximately 44% while maintaining therapeutic efficacy 1, 5.