What is the dosing and administration of Encicarb (iron carbonyl) for a female patient with severe anemia (hemoglobin level less than 8 gm/dl)?

Encicarb (Iron Carbonyl) Administration and Dosing for Severe Anemia

Critical Clarification

Encicarb (iron carbonyl) is an oral iron supplement, not an injectable medication, and should not be used as first-line therapy in a female patient with hemoglobin less than 8 gm/dL. 1

Immediate Management for Hb <8 gm/dL

For a female patient with hemoglobin below 8 gm/dL, red blood cell transfusion should be administered without delay, followed by intravenous iron therapy—not oral iron carbonyl. 2

Transfusion Indications

• Patients with Hb <7-8 g/dL require immediate RBC transfusion to rapidly improve hemoglobin and relieve severe anemia-related symptoms 2
• Transfusion is justified even at higher Hb levels if severe symptomatic anemia is present 2
• Target hemoglobin of 70-90 g/L (7-9 g/dL) is reasonable for most patients 2
• Each unit of packed red cells contains approximately 200-250 mg of elemental iron but does not replenish iron stores 2, 3

Post-Transfusion Iron Repletion

After stabilization with transfusion, intravenous iron—not oral iron carbonyl—should be initiated to replenish iron stores 2

Iron Carbonyl: What It Actually Is

Mechanism of Action

• Iron carbonyl is elemental iron powder that must be oxidized in the stomach to ferrous iron before absorption 4
• It is absorbed similarly to other oral iron preparations but may have reduced toxicity risk in case of accidental overdose 4

Route of Administration

• Oral only—one chewable tablet daily containing 30 mg elemental iron 1
• This is a dietary supplement dose, not therapeutic dosing for severe anemia 1

Why Iron Carbonyl is Inappropriate for Hb <8 gm/dL

Inadequate Dosing

• The standard iron carbonyl dose (30 mg daily) 1 is far below the therapeutic requirement for severe iron deficiency anemia
• Therapeutic oral iron dosing requires 60-120 mg elemental iron daily for women with IDA 2
• Research shows that 1,000-3,000 mg daily of carbonyl iron was needed to correct anemia in clinical studies 4—this is 33-100 times the standard supplement dose

Slow Response Time

• Oral iron (including carbonyl iron) takes at least 2 weeks to show a hemoglobin increase of 10 g/L (1 g/dL) 2
• With Hb <8 g/dL, this slow response is clinically unacceptable when rapid correction is needed 2

Appropriate Treatment Algorithm for Female Patient with Hb <8 gm/dL

Step 1: Immediate Intervention

• Administer RBC transfusion for hemoglobin <8 g/dL 2
• Monitor for symptoms of anemia and cardiovascular compromise 5

Step 2: Determine Iron Status

• Check serum ferritin and transferrin saturation before initiating iron therapy 2
• Absolute iron deficiency: ferritin <100 ng/mL 2
• Functional iron deficiency: transferrin saturation <20% with ferritin >100 ng/mL 2

Step 3: Initiate Intravenous Iron

Intravenous iron is the preferred route for severe anemia (Hb <10 g/dL) 2

IV Iron Dosing Options:

• Iron sucrose (Venofer): 200 mg per dose, maximum 200-300 mg per treatment episode 2
• Ferric carboxymaltose (Ferinject): 500-1,000 mg single dose (up to 20 mg/kg), can be delivered in 15 minutes 2
• Iron dextran (Cosmofer): Up to 20 mg/kg as single infusion over 6 hours 2

Total Iron Deficit Calculation:

• For confirmed iron deficiency: 1,000 mg iron given as single or multiple doses according to product label 2
• Simple dosing scheme (for ferric carboxymaltose): Based on Hb and body weight, typically 1,000-1,500 mg total 2

Step 4: Monitoring Response

• Recheck hemoglobin after 2 weeks of IV iron therapy 2
• Expected response: Hb increase of at least 10 g/L (1 g/dL) within 2 weeks 2
• If no response after 4 weeks despite compliance, further evaluation is needed 2

Step 5: Maintenance Therapy

• Once Hb normalizes, continue iron supplementation for 2-3 months to replenish stores 2
• Monitor Hb every 3 months for 1 year, then annually 2

When Oral Iron (Including Carbonyl Iron) Might Be Considered

Oral iron is only appropriate after:

• Hemoglobin has been stabilized above 10 g/dL 2
• Patient cannot access or tolerate IV iron 2
• Maintenance therapy after IV iron repletion 2

Optimal Oral Iron Regimen (Not Carbonyl Iron)

• 60-120 mg elemental iron on alternate days (not daily) to maximize absorption 6
• Morning dosing preferred over evening 6
• Standard ferrous sulfate (200 mg = 65 mg elemental iron) is more cost-effective than carbonyl iron 2

Critical Pitfalls to Avoid

• Never delay transfusion in favor of oral iron when Hb <8 g/dL 2
• Do not use dietary supplement doses (like standard iron carbonyl 30 mg) for therapeutic treatment of anemia 1
• Avoid oral iron as first-line in severe anemia—IV iron provides faster, more reliable repletion 2
• Do not assume all "iron" products are equivalent—carbonyl iron supplements contain far less elemental iron than therapeutic formulations 1, 4