What is an alternative to ferrous sulfate (iron supplement) tablets for someone who experiences nausea and vomiting?

Alternatives to Ferrous Sulfate for Nausea and Vomiting

Switch to alternate-day dosing of ferrous sulfate (one tablet every other day) as the first-line strategy, or consider ferric maltol if moderate anemia and alternate-day dosing fails, as ferric maltol has GI side effects comparable to placebo. 1

Immediate Dosing Adjustments (Try First)

Before switching formulations, modify the current ferrous sulfate regimen:

• Reduce to alternate-day dosing (one tablet every 48 hours), which significantly reduces nausea while maintaining similar total iron absorption due to decreased hepcidin elevation 1, 2, 3
• If alternate-day dosing still causes symptoms, try taking with food despite reduced absorption—this is preferable to non-compliance 2
• Add 500mg vitamin C with each dose to enhance absorption, especially if taking with food 2, 3

Alternative Oral Iron Formulations

If dosing adjustments fail, switch to these alternatives in order:

First Alternative: Other Ferrous Salts

• Ferrous fumarate (210-322mg tablets containing 69-106mg elemental iron) or ferrous gluconate (300mg tablets containing 37mg elemental iron) may be better tolerated in some patients 1
• These are cost-effective alternatives at similar prices to ferrous sulfate (£1.00-2.18 per 28 days) 1
• Important caveat: Evidence shows no consistent superiority in tolerability between ferrous salts—individual response varies 2, 3

Second Alternative: Ferric Maltol (Best Tolerability)

• Ferric maltol 30mg twice daily has GI side effects comparable to placebo in clinical trials 1, 2
• Normalized hemoglobin in 63-66% of patients with moderate anemia (Hb >95 g/L) after 12 weeks 1
• Trade-off: Significantly more expensive (£47.60 per 28 days vs £1.00 for ferrous sulfate) and slower iron loading due to lower elemental iron content 1
• Best reserved for patients with previous intolerance to traditional iron salts 1

Third Alternative: Liquid Formulations

• Sodium feredate liquid (190mg/5mL containing 27.5mg/5mL elemental iron) may be easier to titrate and tolerate 1
• Cost: £8.37 per 28 days 1

What NOT to Use

Avoid modified-release (MR) preparations of ferrous sulfate—they are less suitable for prescribing due to reduced efficacy and higher cost 1, 2

When to Consider Intravenous Iron

Switch to parenteral iron if:

• Oral iron causes intolerable GI symptoms despite all dosing adjustments and formulation changes 1, 2, 3
• No hemoglobin rise of at least 10 g/L after 2 weeks of daily oral therapy (90% sensitivity for treatment failure) 1
• Parenteral iron produces clinically meaningful hemoglobin response within one week 1

Monitoring Strategy

• Check hemoglobin at 2-4 weeks to assess response 1, 2, 3
• Continue iron for approximately 3 months after hemoglobin normalizes to replenish stores 2, 3
• If no improvement in 2 weeks, strongly consider switching to parenteral iron rather than prolonging oral trials 1

Common Pitfalls to Avoid

• Don't increase dosing frequency—taking iron more than once daily increases side effects without improving absorption due to hepcidin elevation 2, 3
• Don't take with tea or coffee—wait at least one hour, as these powerfully inhibit iron absorption 2, 3
• Don't assume all formulations will cause the same symptoms—individual variation exists, making empiric trials reasonable 2, 4