Parenteral Iron Dosing Multi-calc

Background

Equations used:

Calculation of the Total Iron Deficit - Ganzoni Equation

Total iron deficit [mg] = body weight [kg] x (target Hb-actual Hb) [g/dl] x 2.4 + depot iron [mg].     Pharmacosmos A/S, CosmoFer(R) low molecular weight (Mw) iron dextran. [Package insert] Accessed: March 2019. 

Injectafer prescribing info:  Calculated iron deficit based on the modified Ganzoni formula*: Subject weight in kg x (15 - current hemoglobin g/dL) x 2.4 + 500. If subject TSAT >20% and ferritin >50 ng/mL, the 500-mg constant is not needed.

*Ganzoni AM. Intravenous iron-dextran: therapeutic and experimental possibilities [in German] Schweiz Med Wochenschr. 1970;100(7):301-303.

Calculating the total dose of parenteral iron:

Infed® equation: Adults and Children over 15 kg (33 lbs): Dose (mL) = 0.0442 (Desired Hb - Observed Hb) x LBW + (0.26 x LBW) Desired Hb = the target Hb in g/dl.     Observed Hb = the patient's current hemoglobin in g/dl. LBW = Lean body weight in kg. A patient's lean body weight (or actual body weight if less than lean body weight) should be utilized when determining dosage. For males: LBW = 50 kg + 2.3 kg for each inch of patient's height over 5 feet For females: LBW = 45.5 kg + 2.3 kg for each inch of patient's height over 5 feet. Found in multiple references. Included in the iron dextran package insert.   INFED- iron dextran injection [Package insert]

Simplified method - Estimated of total iron needs:


Jimenez K, Kulnigg-Dabsch S, et al.⁴ stated that the commonly used Ganzoni formula (1st equation above) tended to underestimate the parenteral iron requirements and that a simplified method created by Evstatiev R, Marteau P, et al.⁵ had greater efficacy and was easier to implement.   The program will cross-reference this method and generate a dosage based on the entries above.

 

Parenteral Iron Preparations

Sodium ferric gluconate complex injection [ Ferrlecit ] 
[package insert]  -
Elemental iron:  12.5 mg/mL (5 mL).
Indications:   Ferrlecit is an iron replacement product for treatment of iron deficiency anemia in adult patients and in pediatric patients age 6 years and older with chronic kidney disease receiving hemodialysis who are receiving supplemental epoetin therapy.

Adult Dosage and Administration:   The recommended dosage of Ferrlecit for the repletion treatment of iron deficiency in hemodialysis patients is 10 mL of Ferrlecit (125 mg of elemental iron). Ferrlecit may be diluted in 100 mL of 0.9% sodium chloride administered by intravenous infusion over 1 hour per dialysis session. Ferrlecit may
also be administered undiluted as a slow intravenous injection (at a rate of up to 12.5 mg/min) per dialysis session. For repletion treatment most patients may require a cumulative dose of 1000 mg of elemental iron administered over 8 dialysis sessions. Ferrlecit has been administered at sequential dialysis sessions by infusion or by slow intravenous injection during the dialysis session itself.   Data from Ferrlecit postmarketing spontaneous reports indicate that individual doses exceeding 125 mg may be associated with a higher incidence and/or severity of adverse events.

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Iron Sucrose [ Venofer ]
Elemental iron:   20 mg/mL (2.5 mL, 5 mL, 10 mL)
Solution, Intravenous [preservative free]:

[package insert]
INDICATIONS: Venofer is an iron replacement product indicated for the treatment of iron deficiency anemia in patients with chronic kidney disease (CKD).

DOSAGE AND ADMINISTRATION: Venofer must only be administered intravenously either by slow injection or by infusion. The dosage of Venofer is expressed in mg of elemental iron.  Mode of Administration:  Administer Venofer only intravenously by slow injection or by infusion. The dosage of Venofer is expressed in mg of elemental iron.

Adult Patients with Hemodialysis Dependent-Chronic Kidney Disease (HDD-CKD):
Administer Venofer 100 mg undiluted as a slow intravenous injection over 2 to 5 minutes, or as an infusion of 100 mg diluted in a maximum of 100 mL of 0.9% NaCl over a period of at least 15 minutes, per consecutive hemodialysis session. Administer Venofer
early during the dialysis session (generally within the first hour). The usual total treatment course of Venofer is 1000 mg. Venofer treatment may be repeated if iron deficiency reoccurs.
Adult Patients with Non-Dialysis Dependent-Chronic Kidney Disease (NDD-CKD):
Administer Venofer 200 mg undiluted as a slow intravenous injection over 2 to 5 minutes or as an infusion of 200 mg in a maximum of 100 mL of 0.9% NaCl x 15 minutes. Administer on 5 different occasions over a 14 day period. There is limited experience with administration of an infusion of  500 mg of Venofer, diluted in a maximum of 250 mL of 0.9% NaCl, over a period of 3.5 to 4 hours on Day 1 and Day 14. Venofer treatment may be repeated if iron deficiency reoccurs.

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Ferumoxytol [ Feraheme ]
Elemental iron:  510 mg/17 mL (17 mL) 30 mg/mL

[package insert] 
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Boxed warning REVIEW INSERT.
WARNING: RISK FOR SERIOUS HYPERSENSITIVITY/ANAPHYLAXIS REACTIONS

Fatal and serious hypersensitivity reactions including anaphylaxis have occurred in patients receiving Feraheme. Initial symptoms may include
hypotension, syncope, unresponsiveness, cardiac/cardiorespiratory arrest.

Only administer Feraheme as an intravenous infusion over at least 15 minutes and only when personnel and therapies are immediately available for the
treatment of anaphylaxis and other hypersensitivity reactions. 
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Indications: Feraheme is indicated for the treatment of iron deficiency anemia (IDA) in adult patients:  who have intolerance to oral iron or have had unsatisfactory response to oral iron or who have chronic kidney disease (CKD).

DOSAGE AND ADMINISTRATION:  The recommended dose of Feraheme is an initial 510 mg dose followed by a second 510 mg dose 3 to 8 days later. Administer Feraheme as an intravenous infusion in 50-200 mL 0.9% Sodium Chloride Injection, USP or 5% Dextrose Injection, USP over at least 15 minutes. Administer while the patient is in a
reclined or semi-reclined position.

Feraheme does not contain antimicrobial preservatives. Discard unused portion. Feraheme, when added to intravenous infusion bags containing either 0.9%
Sodium Chloride Injection, USP (normal saline), or 5% Dextrose Injection, USP, at concentrations of 2-8 mg elemental iron per mL, should be used  immediately but may be stored at controlled room temperature (25°C ± 2°C) for up to 4 hours or refrigerated (2-8° C) for up to 48 hours.

The dosage is expressed in terms of mg of elemental iron, with each mL of Feraheme containing 30 mg of elemental iron. Evaluate the hematologic response (hemoglobin, ferritin, iron and transferrin saturation) at least one month following the second Feraheme infusion. The recommended Feraheme dose may be readministered to patients with persistent or recurrent iron deficiency anemia.

For patients receiving hemodialysis, administer Feraheme once the blood pressure is stable and the patient has completed at least one hour of  hemodialysis. Monitor for signs and symptoms of hypotension following each Feraheme infusion.

Allow at least 30 minutes between administration of Feraheme and administration of other medications that could potentially cause serious hypersensitivity reactions and/or hypotension, such as chemotherapeutic agents or monoclonal antibodies.

Inspect parenteral drug products visually for the absence of particulate matter and discoloration prior to administration.

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Ferric Carboxymaltose [ Injectafer ]
Elemental iron:  Injectafer contains 50 mg of elemental iron - 750 mg/15 mL

[package insert]
Indications: Injectafer is indicated for the treatment of iron deficiency anemia in adult patients: who have intolerance to oral iron or have had unsatisfactory response to oral iron;   who have non-dialysis dependent chronic kidney disease.

Dosage:  For patients weighing 50 kg (110 lb) or more: Give Injectafer in two doses separated by at least 7 days. Give each dose as 750 mg for a total  cumulative dose not to exceed 1500 mg of iron per course.

For patients weighing less than 50 kg (110 lb): Give Injectafer in two doses separated by at least 7 days. Give each dose as 15 mg/kg body weight for a total cumulative dose not to exceed 1500 mg of iron per course.
Injectafer treatment may be repeated if iron deficiency anemia reoccurs.

Administer Injectafer intravenously, either as an undiluted slow intravenous push or by infusion. When administering as a slow intravenous push, give at the rate of approximately 100 mg (2 mL) per minute. When administered via infusion, dilute up to 750 mg of iron in no more than 250 mL of sterile  0.9% sodium chloride injection, USP, such that the concentration of the infusion is not less than 2 mg of iron per mL and administer over at least 15 minutes.
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Iron Dextran Complex [ Infed ]
Elemental iron: 50 mg of elemental iron per mL [2 mL]
[package insert]
--------------------------------------------
BOXED WARNING: 
WARNING: RISK FOR ANAPHYLACTIC-TYPE REACTIONS
Anaphylactic-type reactions, including fatalities, have followed the parenteral administration of iron dextran injection.   Have resuscitation equipment and personnel trained in the detection and treatment of anaphylactic-type reactions readily available during INFeD  administration.   Administer a test INFeD dose prior to the first therapeutic dose. If no signs or symptoms of anaphylactic-type reactions follow the test dose,  administer the full therapeutic INFeD dose. During all INFeD administrations, observe for signs or symptoms of anaphylactic-type reactions. Fatal reactions have followed the test dose of iron  dextran injection. Fatal reactions have also occurred in situations where the test dose was tolerated. Use INFeD only in patients in whom clinical and laboratory investigations have established an iron deficient state not amenable to oral iron therapy. Patients with a history of drug allergy or multiple drug allergies may be at increased risk of anaphylactic-type reactions to INFeD.
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INDICATIONS AND USAGE:  Intravenous or intramuscular injections of INFeD are indicated for treatment of patients with documented iron deficiency in whom oral administration is unsatisfactory or impossible.

DOSAGE AND ADMINISTRATION:  Oral iron should be discontinued prior to administration of INFeD.
I. Iron Deficiency Anemia: Periodic hematologic determination (hemoglobin and hematocrit) is a simple and accurate technique for monitoring  hematological response, and should be used as a guide in therapy. It should be recognized that iron storage may lag behind the appearance of normal  blood morphology. Serum iron, total iron binding capacity (TIBC) and percent saturation of transferrin are other important tests for detecting and  monitoring the iron deficient state.

After administration of iron dextran complex, evidence of a therapeutic response can be seen in a few days as an increase in the reticulocyte count.

The total amount of INFeD in mL required to treat the anemia and replenish iron stores may be approximated as follows:

Adults and Children over 15 kg (33 lbs): See Dosage Table. Alternatively the total dose may be calculated:

Dose (mL) = 0.0442 (Desired Hb - Observed Hb) x LBW + (0.26 x LBW)
Based on: Desired Hb = the target Hb in g/dl.
Observed Hb = the patient's current hemoglobin in g/dl.
LBW = Lean body weight in kg. A patient's lean body weight (or actual body weight if less than lean body weight) should be utilized when determining dosage.
For males: LBW = 50 kg + 2.3 kg for each inch of patient's height over 5 feet
For females: LBW = 45.5 kg + 2.3 kg for each inch of patient's height over 5 feet

Administration:
I. Intravenous Injection - PRIOR TO THE FIRST INTRAVENOUS INFeD THERAPEUTIC DOSE, ADMINISTER AN INTRAVENOUS TEST DOSE OF 0.5 ML. ADMINISTER THE TEST DOSE AT A GRADUAL RATE OVER AT LEAST 30 SECONDS. Although anaphylactic reactions known to occur following INFeD administration are usually evident
within a few minutes, or sooner, it is recommended that a period of an hour or longer elapse before the remainder of the initial therapeutic dose is  given.

Individual doses of 2 mL or less may be given on a daily basis until the calculated total amount required has been reached. INFeD is given undiluted at  a slow gradual rate not to exceed 50 mg (1 mL) per minute.

https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=abacb7fa-2fc2-471e-9200-944eeac8ca2a

References

1. Pharmacosmos A/S, CosmoFer(R) low molecular weight (Mw) iron dextran. [Package insert] Accessed: March 2019.
   
   
2. Alldredge BK, Corelli RL, Ernst ME, Guglielmo BJ, eds. Anemias. In: Koda-Kimble & Young's Applied Therapeutics: The Clinical Use of Drugs. 10th ed. Philadelphia, PA: Lippincott Williams & Wilkins;2013;303-307.
   
   
3.  Schrier SL, Mentzer WC, Landaw SA. Treatment of anemia due to iron deficiency. UpToDate(R). 2010;18(3). https://www.uptodate.com/ (Requires subscription). Accessed: 4/12/2011.
   
   
4. Jimenez K, Kulnigg-Dabsch S, Gasche C. Management of Iron Deficiency Anemia. Gastroenterol Hepatol (N Y). 2015;11(4):241-50.
   
   
5. Evstatiev R, Marteau P, Iqbal T, Khalif IL, Stein J, Bokemeyer B, Chopey IV, Gutzwiller FS, Riopel L, Gasche C; FERGI Study Group. FERGIcor, a randomized controlled trial on ferric carboxymaltose for iron deficiency anemia in inflammatory bowel disease. Gastroenterology. 2011 Sep;141(3):846-853.e1-2.   [Pubmed]
   
   
6. Auerbach M, Witt D, Toler W, Fierstein M, Lerner RG, Ballard H. Clinical use of the total dose intravenous infusion of iron dextran. J Lab Clin Med. 1988 May;111(5):566-70.
   
   
7.  Bhowmik D, Modi G, Ray D, Gupta S, Agarwal SK, Tiwari SC, Dash SC. Total dose iron infusion: safety and efficacy in predialysis patients. Ren Fail. 2000 Jan;22(1):39-43.
   
   
8. Burns DL, Mascioli EA, Bistrian BR. Parenteral iron dextran therapy: a review. Nutrition. 1995 Mar-Apr;11(2):163-8.
   
   
9. Case G. Maintaining iron balance with total-dose infusion of intravenous iron dextran. ANNA J. 1998 Feb;25(1):65-8.
   
   
10. Hanson DB, Hendeles L. Guide to total dose intravenous iron dextran therapy. Am J Hosp Pharm. 1974 Jun;31(6):592-5.
    
    
11. Jacobs P, Dommisse J. The plasma ferritin level as a reliable index of body iron stores following intravenous iron dextran. J Med. 1982;13(4):309-21.
    
    
12. Kumpf VJ. Parenteral iron supplementation. Nutr Clin Pract. 1996 Aug;11(4):139-46.
    
    
13. Kumpf VJ, Holland EG. Parenteral iron dextran therapy. DICP. 1990 Feb;24(2):162-6.