What is the recommended dosing and administration of Ferrex‑150 (polysaccharide‑iron complex) for adults and children?

Ferrex-150 Dosing for Iron Deficiency Anemia

Ferrex-150 (polysaccharide-iron complex) should be dosed at 150 mg of elemental iron once daily in adults, which is the standard formulation strength for this product. 1

Adult Dosing

• Standard dose: 150 mg elemental iron once daily 1
• Alternative regimen for symptomatic patients: Up to 200 mg elemental iron daily, divided into 2-3 doses, though this exceeds the single Ferrex-150 capsule strength 1
• Optimal absorption: Administer on an empty stomach without food or other medications to maximize intestinal iron uptake 1

Pediatric Dosing

• Weight-based dosing: 2-3 mg/kg/day of elemental iron in children 1
• Polysaccharide-iron complex formulations are available but specific pediatric safety data for Ferrex-150 are limited in FDA labeling 1

Duration of Therapy

• Treatment course: Continue oral iron for 3-12 weeks to correct anemia and replenish iron stores 2
• Monitoring interval: Reassess hemoglobin and iron parameters at 4-8 weeks to evaluate response 3

Cost Considerations

• Monthly cost: Approximately $7.12 for 150 mg elemental iron daily, making polysaccharide-iron complex more expensive than ferrous sulfate ($2.29/month) or ferrous fumarate ($1.63/month) 1
• Despite higher cost, polysaccharide-iron complex may offer better gastrointestinal tolerability in selected patients 1

When Oral Iron Fails

• Inadequate response threshold: If hemoglobin fails to increase by 1-2 g/dL within 4-8 weeks, consider switching to intravenous iron 3
• Indications for IV iron: Intolerance to oral iron, malabsorption disorders, active inflammatory bowel disease, need for rapid correction (hemoglobin <10 g/dL), or chronic kidney disease 4
• Preferred IV formulations: Ferric carboxymaltose (750-1000 mg per dose) or ferric derisomaltose (1000-1500 mg single dose) allow complete repletion in 1-2 visits versus 8 weekly visits required for ferric gluconate 5, 3

Common Pitfalls to Avoid

• Do not combine oral and IV iron: Concurrent use increases side effects without additional benefit 5
• Do not dose more frequently than once daily: Recent evidence shows once-daily dosing (or even alternate-day dosing) is as effective as multiple daily doses while reducing gastrointestinal side effects 6
• Do not continue indefinitely without monitoring: Check complete blood count and iron studies at 4-8 weeks to assess response and avoid iron overload 3
• Do not expect immediate results: Hemoglobin typically begins rising within 1-2 weeks but full correction requires 4-8 weeks 3

Absorption Considerations

• Reduced absorption with food: Concurrent food intake significantly impairs iron absorption 1
• Drug interactions: Separate administration from calcium supplements, antacids, proton pump inhibitors, and tetracycline antibiotics by at least 2 hours 1
• Hepcidin effect: In patients with chronic inflammation or chronic kidney disease receiving erythropoiesis-stimulating agents, oral iron absorption may be severely limited despite adequate dosing 1