Ferrous Citrate Fe 59 (Systemic)


VA CLASSIFICATION
Primary: DX201

Note: For a listing of dosage forms and brand names by country availability, see Dosage Forms section(s).

*Not commercially available in the U.S.



Category:


Diagnostic aid (iron metabolism; iron absorption)—

Indications

Accepted

Anemia (diagnosis) and
Iron metabolism studies—Ferrous citrate Fe 59 is indicated, by intravenous administration, to determine various parameters of the kinetics of iron metabolism, including plasma iron clearance, plasma iron turnover rate, and the utilization of iron in new red blood cells. The values of serum iron obtained from these studies provide diagnostic information in patients with anemias. {02} {03} {06} {08} Ferrous citrate Fe 59 is also useful to assess the role of the spleen in red blood cell production and destruction, and thus to help determine the advisability of splenectomy. Also, organ uptake measurements are used to measure the sites of red cell production (or lack thereof) in extramedullary erythropoiesis in myeloproliferative disorders. {07}

Iron absorption studies—Ferrous citrate Fe 59 is indicated, by oral administration, to measure the absorption of iron from the intestine. {06}


Physical Properties

Nuclear data: {01} {04} {06}



Radionu-
clide
(half-life)
Decay
constant
Mode
of
decay
Principal
emissions
(meV)
Mean
number of
emissions/
disintegration
Fe 59
(44.6
days)
0.000649 hr -1
Beta
emission
Beta-2
(mean
0.081)
0.45
      Beta-3
(mean
0.149)
0.53
      Gamma-2
(0.192)
0.03
      Gamma-5
(1.099)
0.56
      Gamma-6
(1.292)
0.43


Pharmacology/Pharmacokinetics

Mechanism of action/Effect:

Iron from ferrous citrate is bound to plasma protein (transferrin) and carried to the blood-forming organs where it is utilized to form hemoglobin or is deposited in the reticuloendothelial cells of the liver and spleen. The amount of radioactive iron absorbed, transported, stored, utilized, and excreted can then be measured by the periodic collection of blood specimens and external counting. {02} {06}

Protein binding:

Very high.

Half-life:


Plasma iron clearance (biological):

Normal: 1 to 2 hours.

Polycythemia, iron deficiency anemia, chronic blood loss, and hemolytic anemia: < 1 hour.

Hypoplastic anemia, myelofibrosis, and hemachromatosis: > 2 hours. {02} {04}


Note: Transferrin-bound radioactive iron concentration in plasma decreases as radioactive iron accumulates in the bone marrow. Rate of disappearance reflects erythropoiesis.


Radiation dosimetry:
{04}{07}

Mode
of
administration
Estimated absorbed radiation dose *
Target
organ
mGy/MBq
rad/mCi
Intravenous
Spleen
55
200
  Heart wall
24
90
  Liver
12
44
  Red marrow
12
43
  Kidneys
8.6
32
  Ovaries
6.4
24
  Testes
5.3
20
  Total body
6.4
24
* In normal subjects.

Elimination:
    No significant physiological system of excretion exists for iron. Very slowly excreted, mostly in feces; remainder excreted within cells shed by skin and gastrointestinal mucosa.


Precautions to Consider

Pregnancy/Reproduction

Pregnancy—
The possibility of pregnancy should be assessed in women of child-bearing potential. Clinical situations exist where the benefit to the patient and fetus derived from radiopharmaceutical use outweighs the risks from radiation exposure to the fetus. In these situations, the physician should use discretion and reduce the radiopharmaceutical dose to the lowest possible amount. {05} {09}

Breast-feeding

Ferrous citrate Fe 59 is excreted in breast milk. Because of the potential risk of radiation exposure to the infant, temporary discontinuation of nursing is recommended for a length of time that may be assessed by measuring the activity of breast milk and estimating the radiation exposure to the infant.

Pediatrics

There have been no specific studies evaluating safety and efficacy of ferrous citrate Fe 59 in children. When this radiopharmaceutical is used in children, the diagnostic benefit should be judged to outweigh the potential risk of radiation. {09}


Geriatrics


Appropriate studies on the relationship of age to the effects of ferrous citrate Fe 159 have not been performed in the geriatric population. However, no geriatrics-specific problems have been documented to date.

Diagnostic interference
The following have been selected on the basis of their potential clinical significance (possible effect in parentheses where appropriate)—not necessarily inclusive (» = major clinical significance):

With results of this test
Foods    (absorption of oral ferrous citrate Fe 59 may be decreased by presence of food in the stomach; overnight fasting is recommended prior to its administration for iron absorption studies {07})



Side/Adverse Effects
At present, there are no known side/adverse effects associated with the use of ferrous citrate Fe 59. {06}



Patient Consultation
As an aid to patient consultation, refer to Advice for the Patient, Radiopharmaceuticals (Diagnostic).

In providing consultation, consider emphasizing the following selected information (» = major clinical significance):

Description of use
Action in the body: Utilization by body of radioactive iron same as dietary iron

Collection of blood specimen allows measurement of iron

Small amounts of radioactivity used in diagnosis; radiation received is low and considered safe

Before having this test
»   Conditions affecting use, especially:

Pregnancy—Risk of radiation exposure to fetus





Breast-feeding—Excreted in breast milk; temporary discontinuation of nursing recommended because of risk of radiation exposure to infant





Use in children—Risk of radiation exposure


Preparation for this test
Special preparatory instructions may be given; patient should inquire in advance

Precautions after having this test
No special precautions


General Dosing Information
Radiopharmaceuticals are to be administered only by or under the supervision of physicians who have had extensive training in the safe use and handling of radionuclides and who are licensed by the Nuclear Regulatory Commission (NRC) or the appropriate Agreement State agency or, outside the U.S., the appropriate authority. {07}

Overnight fasting is recommended prior to the oral administration of ferrous citrate Fe 59 for iron absorption studies. {07}

Safety considerations for handling this radiopharmaceutical
Improper handling of this radiopharmaceutical may cause radioactive contamination. Guidelines for handling radioactive material have been prepared by scientific, professional, state, federal, and international bodies and are available to the specially qualified and authorized users who have access to radiopharmaceuticals. {10}


Parenteral Dosage Forms

FERROUS CITRATE Fe 59 INJECTION USP

Usual adult and adolescent administered activity
Diagnostic aid
Intravenous or oral, 0.185 to 0.555 megabecquerel (5 to 15 microcuries). {06}


Usual pediatric administered activity
Diagnostic aid
Dosage must be individualized by physician.


Usual geriatric administered activity
See Usual adult and adolescent administered activity .

Strength(s) usually available
U.S.—
Not commercially available.

Canada—


0.185 to 3.7 megabecquerels (5 to 100 microcuries) per mL, having a specific activity ranging from 0.185 to 1.11 megabecquerels (5 to 30 microcuries) per microgram of iron, at time of calibration (Rx)[Generic]

Packaging and storage:
Store below 40 °C (104 °F), preferably between 15 and 30 °C (59 and 86 °F), unless otherwise specified by manufacturer. {06}

Note: Caution—Radioactive material.




Revised: 08/02/1994



References

Note: All references used in the development and earlier revisions of this monograph have not yet been incorporated into the computer database and, therefore, are not listed below. Citations for information not yet referenced in the monograph will be provided upon request.

  1. Package insert (Mallinckrodt 6/80).
  1. Maynard CD. Clinical nuclear medicine. Philadelphia: Lea and Febiger, 1971: 76.
  1. Chilton HM, Witcofski RL. Nuclear pharmacy—An introduction to the clinical application of radiopharmaceuticals. Philadelphia: Lea and Febiger, 1986: 114-116.
  1. Loevinger R, Budinger T, Watson E. MIRD primer for absorbed dose calculations. New York: The Society of Nuclear Medicine, 1988: 85.
  1. Panel comments as per 1/1988 meeting.
  1. Product information from Frosst, Canada 7/88.
  1. Reviewers' responses to monograph revision of 6/29/88.
  1. Maisey MN, Britton KE, Gilday DL. Clinical nuclear medicine. 2nd ed. Philadelphia: J.B. Lippincott, 1991: 356.
  1. Panel meeting 5/91.
  1. Reviewers' responses to Ballot of 5/11/94.
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