What are the recommended drugs and dosages for treating iron deficiency anemia?

Recommended Drugs and Dosages for Iron Deficiency Anemia

Oral ferrous sulfate 200 mg twice daily is the first-line treatment for iron deficiency anemia due to its effectiveness, simplicity, and low cost. 1

Oral Iron Therapy

First-Line Oral Iron Options:

• Ferrous sulfate: 200 mg twice daily (contains approximately 65 mg elemental iron per tablet) 1
• Ferrous gluconate: 300 mg daily (contains 27-38 mg elemental iron per tablet) 1
• Ferrous fumarate: 200 mg daily (contains 65-106 mg elemental iron per tablet) 1

Dosing Considerations:

• Treatment should continue for 3 months after hemoglobin normalization to replenish iron stores 1
• Lower doses may be equally effective and better tolerated in patients experiencing side effects 1
• Hemoglobin should rise by approximately 2 g/dL after 3-4 weeks of therapy 1
• Adding ascorbic acid (250-500 mg twice daily) may enhance iron absorption when response is poor 1

Monitoring:

• Monitor hemoglobin and red cell indices at 3-month intervals for the first year after normalization, then after another year 1
• Additional oral iron should be given if hemoglobin or MCV falls below normal 1

Intravenous Iron Therapy

Indications for IV Iron:

• Intolerance to at least two oral iron preparations 1
• Poor compliance with oral therapy 1
• Clinically active inflammatory bowel disease 1
• Hemoglobin below 10 g/dL 1
• Patients after bariatric surgery (impaired absorption) 1
• When iron loss exceeds oral iron absorption capacity 1

IV Iron Formulations:

• Ferric carboxymaltose (Ferinject/Injectafer): 750-1000 mg per dose, can be given as single dose or two 750 mg doses one week apart 1

  • Special consideration: Risk of hypophosphatemia 1

• Iron sucrose (Venofer): 200 mg per dose, given as 5 doses of 200 mg or 3 doses of 300 mg weekly 1

  • Can be administered over 10 minutes (bolus) 1

• Ferric derisomaltose/iron isomaltoside (Monofer): 1000 mg as single dose 1

• Low-molecular-weight iron dextran (Cosmofer): 20 mg/kg or 1000 mg as single dose 1

  • Can be given IV or IM (though IM is painful and requires multiple injections) 1
  • Requires test dose due to risk of anaphylactic reactions 1

• Ferumoxytol (Feraheme): 510 mg per dose, given as two doses or single 1020 mg dose 1

  • Special consideration: Notify radiologist if MRI needed within 3 months of infusion 1

Dosing Based on Severity and Patient Weight

For IV iron dosing in inflammatory bowel disease patients 1:

• Hemoglobin 10-12 g/dL (women) or 10-13 g/dL (men):

  • Weight <70 kg: 1000 mg
  • Weight ≥70 kg: 1500 mg

• Hemoglobin 7-10 g/dL:

  • Weight <70 kg: 1500 mg
  • Weight ≥70 kg: 2000 mg

Special Considerations

• Safety precautions: Resuscitation facilities should be available when administering IV iron due to risk of anaphylactic reactions 1
• Cost implications: IV iron is substantially more expensive than oral formulations 1
• Weekly dosing: Some evidence suggests weekly iron supplementation may improve compliance while maintaining efficacy 2
• Tolerability: Extended-release formulations may improve adherence due to better gastrointestinal tolerability 3
• Response assessment: If hemoglobin doesn't rise after 3-4 weeks, consider poor compliance, misdiagnosis, continued blood loss, or malabsorption 1

Pitfalls to Avoid

• Insufficient treatment duration: Failing to continue iron therapy for 3 months after hemoglobin normalization can lead to recurrence 1
• Overlooking underlying causes: Always treat the underlying cause of iron deficiency while supplementing iron 1
• Diphenhydramine use during IV reactions: Should be avoided as its side effects can be mistaken for worsening of the reaction 1
• Overestimating IV iron benefits: While initial hemoglobin rise is more rapid with IV iron, the hemoglobin at 12 weeks is similar to oral iron therapy 1