Iron Dextran is an injectable low-molecular-weight ferric hydroxide complex indicated for patients with iron deficiency anemia where oral iron therapy is ineffective or poorly tolerated. It is particularly useful in iron deficiency resulting from excessive iron loss (e.g., hereditary hemorrhagic telangiectasia, excessive blood loss, etc.) or iron malabsorption (e.g., Crohn disease, celiac disease, inflammatory bowel disease, gastric bypass, etc.). Appropriate uses also include iron deficiency anemia resulting from menometrorrhagia, pregnancy, and surgical blood loss.
Iron dextran is ingested via endocytosis by the macrophages of the reticuloendothelial system. The fusion of the newly formed endosome with acidic lysosome results in the cleavage of the carbohydrate shell and the release of ferrous iron (Fe[2+]). Following release from its complex, Fe(2+) is shuttled across the endolysosomal membrane into the cytoplasm via divalent metal transporter 1 (DMT1), where it can be stored as a Fe-ferritin complex or get shuttled into the blood via ferroportin, a transmembrane protein. Once in the blood, Fe(2+) is immediately oxidized to ferric iron (Fe[3+]) by ceruloplasmin and subsequently bound by transferrin for transport to various sites throughout the body for utilization (i.e.,, to bone marrow for hemoglobin synthesis or to the liver for storage).Hematologic responses of iron dextran may be observed within 3 to 10 days.
Although iron dextran has historically correlated with significant rates of adverse drug events, a retrospective review by Chertow et al. demonstrated that the majority of reported events were from the use of high-molecular-weight formulations of iron dextran, which are no longer available on the market. In contrast to older formulations, few major adverse drug reactions (1 in 25000) have been reported with low-molecular-weight formulations currently available. Although relatively rare, significant adverse drug reactions (2.47%) remain a concern for patient safety and may include death, anaphylactoid reaction (0.61%), allergic reaction, facial edema, pruritis, urticaria, back pain, tachycardia, cardiac arrest, chest pain, dyspnea, respiratory depression, hypotension, nausea, emesis, arthralgia, and diaphoresis.
Intramuscular infusions may additionally be associated with gluteal sarcomas and the following at the injection site: cellulitis, fibrosis, phlebitis, permanent skin discoloration, and localized myalgia. Other adverse reactions include abdominal pain, diarrhea, dysgeusia, leukocytosis, lymphadenopathy, purpuric rash, fever, chills, disorientation, headache, numbness, paresthesia, seizure syncope, and wheezing.
Administration is contraindicated in patients with a known hypersensitivity to iron dextran. Additionally, iron dextran is contraindicated in any form of anemia, which is not the result of iron deficiency. Co-administration with dimercaprol should be avoided as iron-dimercaprol chelates are especially toxic to renal tissue. Patients taking angiotensin-converting enzyme inhibitors may be at an elevated risk of developing adverse reactions. Additionally, caution is necessary when administering iron dextran to patients with any disease states that mimic known major adverse effects; disease states of concern include atopy, asthma, rheumatoid arthritis, and cardiovascular disease.
Appropriate knowledge, training, and cooperation of all interprofessional healthcare team members are vital to patient safety during the administration of iron dextran preparations. Proper evaluation regarding the appropriateness for parenteral iron (i.e., iron dextran) is necessary from prescribing clinicians. Consultation with pharmacists may help prevent errors, including appropriateness of drug use, dosage calculations, interactions, and pertinent dosage modifications. Medical professionals with training in anaphylactoid-type reactions should also be present during the administration of parental iron. Additionally, patient monitoring by nurses following administration will allow for the evaluation of therapeutic response and early detection of adverse drug reactions. Through proper training, open interprofessional communication, and cooperation, healthcare teams will be better equipped to facilitate the delivery of quality patient-centered care and improve overall patient outcomes.