iron dextran


iron

 (Fe) [i´ern] a chemical element, atomic number 26, atomic weight 55.847. (See Appendix 6-1.) Iron is chiefly important to the human body because it is the main constituent of hemoglobin, cytochrome, and other components of respiratory enzyme systems. A constant although small intake of iron in food is needed to replace erythrocytes that are destroyed in the body processes. Most iron reaches the body in food, where it occurs naturally in the form of iron compounds. These are converted for use in the body by the action of the hydrochloric acid produced in the stomach. This acid separates the iron from the food and combines with it in a form that is readily assimilable by the body. Vitamin C enhances absorption of iron, and alkalis hamper absorption.Iron Deficiencies. The amount of new iron needed every day by the adult body is about 18 mg. A child needs more in proportion to weight. Although these amounts are very small, iron deficiencies may cause serious disorders. Three stages of iron deficiency are distinguished: iron depletion or prelatent iron deficiency, in which bodily stores are mildly depleted but no change in hematocrit or serum iron levels is detectable; latent iron deficiency, in which the serum iron level has dropped but the hematocrit is unchanged and there is no anemia; and anemia" >iron deficiency anemia, a serious condition characterized by low to absent iron stores, low hematocrit, and other blood abnormalities. A great loss of blood, such as may result from bleeding ulcers, hemorrhoids, or injury, is the most common cause of a deficiency of iron. Women who lose much blood in menstruation may have to supplement their diet with iron-rich food. Iron deficiency sometimes occurs in pregnancy as a result of increased demands on the mother's blood. It may also occur in infants, since milk contains little iron. Although babies are born with an extra supply of hemoglobin, by the age of 2 or 3 months they need iron-rich food to supplement milk.
Iron preparations, such as ferrous sulfate, may be necessary in the treatment of iron deficiency anemia; they should be administered after meals, never on an empty stomach. The patient should be warned that the drugs cause stools to turn dark green or black. Overdosage may cause severe systemic reactions.
An acute iron deficiency may warrant parenteral administration of an iron supplement. Hypersensitivity to iron supplements often occurs in patients with other known allergies. In other patients the parenteral administration of iron can cause vomiting, chills, fever, headache, joint pain, and urticaria.
Food Sources of Iron. Liver is the richest source of iron; 200 g (6 ounces) of liver contains a whole day's supply for an adult. Other iron-rich foods include lean meat, oysters, kidney beans, whole wheat bread, kale, spinach, egg yolk, turnip greens, beet greens, carrots, apricots, and raisins.Iron metabolism. Uptake of heme iron or ferrous iron occurs in the intestine. From the intestine, iron is transported on transferrin to the liver or the bone marrow. Transferrin binds to red blood precursors in the bone marrow and delivers iron for incorporation into hemoglobin. Red blood cells in the circulation contain 60 percent to 80 percent of body iron. Old red blood cels are destroyed in the spleen. The iron is bound to transferrin for recirculation. Approximately 20 percent to 30 percent of iron is stored in the form of hemosiderin in the spleen, liver, and bone marrow. The remaining iron is in the respiratory enzymes of somatic cells. Iron is lost by desquamation of skin and intestinal cells. From Damjanov, 2000.
iron 59 a radioisotope of iron having a half-life of 44.5 days; used in ferrokinetics tests to determine the rate at which iron is cleared from the plasma and incorporated in red blood cells. Symbol 59Fe.iron dextran a complex of iron and dextran of low molecular weight; administered intravenously or intramuscularly as a hematinic.iron poisoning poisoning from ingestion of excessive iron or iron-containing compounds, such as in children who eat iron supplement tablets like candy; symptoms include ulceration of the gastrointestinal tract, vomiting, vasodilation with shock, metabolic acidosis, liver injury, and coagulation disturbances.iron storage disease hemochromatosis.iron sucrose a complex of ferric hydroxide, Fe(OH)3, in sucrose; used intravenously to treat anemia" >iron deficiency anemia in hemodialysis patients receiving supplemental erythropoietin therapy.

iron dextran

Cosmofer (UK), DexFerrum, InFeD

Pharmacologic class: Trace element

Therapeutic class: Iron supplement

Pregnancy risk category C

FDA Box Warning

• Parenteral use has caused anaphylactictype reactions, some resulting in death. Use only in patients with clearly established indications when laboratory tests confirm iron deficiency not amenable to oral iron therapy. Give drug only where resuscitation techniques and treatment of anaphylactic and anaphylactoid shock are readily available.

Action

Replenishes depleted stores of iron (a component of hemoglobin) in bone marrow

Availability

Injection: 50 mg/ml

Indications and dosages

Iron-deficiency anemia in patients who can't tolerate oral iron

Adults and children weighing more than 15 kg (33 lb): Dosage individualized based on patient's weight and hemoglobin (Hgb) value, using the following formula: Dosage (ml) = 0.0442 (desired Hgb minus patient's Hgb) times lean body weight (LBW) plus the product of 0.26 times LBW

Give test dose before starting I.V. or I.M. therapy: For I.V. use, administer test dose of 0.5 ml (25 mg) I.V. over 30 seconds to 5 minutes; if no reactions occur within 1 hour, give remainder of therapeutic dose I.V.; repeat this dose daily. For I.M. use, give test dose of 0.5 ml (25 mg) by Z-track method; if no reactions occur, give daily doses not exceeding 100 mg I.M. in adults, 50 mg I.M. in children weighing more than 10 kg (22 lb), or 25 mg in infants weighing less than 5 kg (11 lb).

Iron replacement caused by blood loss

Adults: Dosage individualized based on the following formula: Replacement iron (in mg) = blood loss (in ml) times hematocrit

Contraindications

• Hypersensitivity to drug, alcohol, tartrazine, or sulfites

• Acute phase of infectious renal disease or hemolytic anemia

Precautions

Use cautiously in:

• autoimmune disorders, arthritis, severe hepatic impairment

• elderly patients

• breastfeeding patients

• children.

Administration

• For I.M. administration, inject by Z-track method into upper outer quadrant of gluteal muscle.

• For intermittent I.V. infusion, administer undiluted at a rate no faster than 1 ml/minute.

• Don't give with oral iron preparations.

Adverse reactions

CNS: dizziness, headache, syncope, seizures

CV: chest pain, tachycardia, hypotension

GI: nausea, vomiting

Hematologic: hemochromatosis, hemolysis, hemosiderosis

Musculoskeletal: joint pain, myalgia

Respiratory: dyspnea

Other: abnormal or metallic taste, tooth discoloration, fever, lymphadenopathy, hypersensitivity reactions including anaphylaxis

Interactions

None significant

Patient monitoring

See Monitor for hypersensitivity reaction. Keep epinephrine and other emergency supplies on hand in case reaction occurs.

• Assess serum ferritin levels regularly, because these levels correlate with iron stores.

• In patients with rheumatoid arthritis, monitor for acute exacerbation of joint pain and swelling. Provide appropriate comfort measures.

• Watch for signs and symptoms of iron overload, including decreased activity, sedation, and GI or respiratory tract bleeding.

Patient teaching

• Caution patient not to take oral iron preparations or vitamins containing iron during therapy.

• Instruct patient to report difficulty breathing, itching, or rash.

• Tell patient he'll undergo periodic blood testing to monitor his response to therapy.

• As appropriate, review all other significant and life-threatening adverse reactions mentioned above.

iron dextran

An iron hydroxide dextran complex given by injection to treat iron deficiency anaemia in adults who have shown intolerance to oral iron preparations. The drug is on the WHO official list.