What is the appropriate Monoferric (ferric maltol) dosing regimen for an adult with iron‑deficiency anemia, including duration, dose adjustments for gastrointestinal side effects, maximum elemental iron limits, and considerations for chronic kidney disease, inflammatory bowel disease, children, and pregnancy?

Monoferric (Ferric Maltol) Dosing

For adults with iron-deficiency anemia, ferric maltol should be dosed at 30 mg twice daily (morning and evening), taken on an empty stomach at least 1 hour before meals, and continued until hemoglobin normalizes plus an additional 3 months to replete iron stores. 1, 2

Standard Dosing Regimen

• The approved dose is 30 mg ferric maltol twice daily (total 60 mg elemental iron per day), taken in the morning and evening. 2, 3
• Each dose should be taken on an empty stomach, at least 1 hour before food, to maximize absorption. 1
• Treatment duration should continue for approximately 3 months after hemoglobin normalizes to ensure adequate repletion of marrow iron stores. 4

Expected Response and Monitoring

• Hemoglobin should increase by at least 10 g/L (1 g/dL) within 2 weeks of starting therapy; failure to achieve this rise strongly predicts treatment failure (sensitivity 90.1%, specificity 79.3%). 4, 5
• Monitor hemoglobin within the first 4 weeks to confirm adequate response. 4, 5
• Ferritin, transferrin saturation, and serum iron should show progressive increases over the treatment course. 2, 3
• In clinical trials, hemoglobin improvements were sustained up to 52 weeks with continued ferric maltol therapy. 2

Dose Adjustments for Gastrointestinal Side Effects

• Do not reduce the dose below 30 mg twice daily, as lower doses (30 mg once daily) have not been adequately studied and may be insufficient for iron repletion. 3
• Gastrointestinal adverse events with ferric maltol are comparable to placebo and significantly lower than with ferrous sulfate. 4, 1
• If intolerable GI symptoms occur despite the favorable tolerability profile, consider switching to intravenous iron rather than dose reduction, as oral iron may be fundamentally unsuitable for that patient. 4, 5
• The most common adverse events are gastrointestinal (41% in clinical trials), but discontinuation rates are low (6-9%). 2

Maximum Elemental Iron Limits

• The standard ferric maltol regimen provides 60 mg elemental iron per day (30 mg twice daily), which is within safe limits. 3
• Do not exceed 100 mg elemental iron per day in patients with inflammatory bowel disease, as higher doses may exacerbate intestinal inflammation. 6
• Avoid iron overload by monitoring transferrin saturation and ferritin; transferrin saturation above 50% and serum ferritin above 800 μg/L should serve as upper limits for guiding therapy. 6

Special Population: Chronic Kidney Disease

• Ferric maltol at 30 mg twice daily is effective and well-tolerated in patients with stage 3-4 CKD (non-dialysis-dependent) and iron-deficiency anemia. 2, 7
• In a randomized trial of 167 CKD patients, ferric maltol produced a statistically significant increase in hemoglobin of 0.5 g/dL at 16 weeks compared to placebo (P=0.01). 2
• Hemoglobin levels were sustained up to week 52 in CKD patients continuing ferric maltol therapy. 2
• Ferric maltol is approved in the United States and Europe for iron-deficiency anemia in adult patients, including those with CKD. 1, 7
• For CKD patients with estimated GFR < 45 mL/min, consider intravenous iron as the preferred route if oral therapy fails. 4

Special Population: Inflammatory Bowel Disease

• Ferric maltol is particularly well-suited for IBD patients with a history of intolerance to ferrous sulfate, as it demonstrates effectiveness with a preferred adverse event profile. 6
• Use ferric maltol only in patients with clinically inactive IBD; avoid all oral iron during active intestinal inflammation, as luminal iron may exacerbate disease activity. 6, 4
• Limit to 100 mg elemental iron per day maximum in IBD patients (the standard 30 mg twice daily dose provides 60 mg, which is appropriate). 6
• After successful treatment, monitor for recurrent iron deficiency every 3 months for at least a year, then every 6-12 months thereafter. 6
• Re-treat when serum ferritin drops below 100 μg/L or hemoglobin falls below 12 g/dL (women) or 13 g/dL (men). 6

Special Population: Children

• Ferric maltol has been studied in adolescents with iron-deficiency anemia, but specific pediatric dosing data are limited. 1
• The evidence base for ferric maltol primarily involves adults and adolescents, with clinical trials including almost 750 patients. 1
• For younger children, conventional ferrous salts remain the standard, as ferric maltol approval and dosing are established only for adults. 4

Special Population: Pregnancy

• No specific data exist for ferric maltol use in pregnancy; the clinical trials excluded pregnant women. 1, 2
• For pregnant women with iron-deficiency anemia, conventional ferrous sulfate (60-120 mg elemental iron daily) remains the evidence-based standard. 4
• If ferrous sulfate is not tolerated in pregnancy, intravenous iron is preferred over ferric maltol, given the lack of safety data in pregnancy for ferric maltol. 4, 5

When to Escalate to Intravenous Iron

• Switch to intravenous iron if hemoglobin fails to rise by at least 10 g/L at 2 weeks, as this strongly predicts oral therapy failure. 4, 5
• Intravenous iron is first-line for patients with active IBD, severe malabsorption, or ongoing blood loss where oral iron is fundamentally unsuitable. 4, 5
• Modern IV formulations (ferric carboxymaltose, ferric derisomaltose) can replenish total body iron stores in one or two infusions and produce clinically meaningful hemoglobin response within one week. 4, 5

Cost Considerations

• Ferric maltol is substantially more expensive than ferrous sulfate (£47.60 vs £1.00 per 28-day supply), but offers superior tolerability in patients who cannot tolerate conventional iron salts. 4, 5
• The higher cost is justified when previous intolerance to ferrous sulfate has been documented or when IBD-specific considerations favor a better-tolerated formulation. 6, 4