What are the potential adverse effects of intravenous iron therapy in an 86-year-old patient with iron deficiency?

From the Guidelines

Iron infusions for an 86-year-old can cause several side effects, including temporary low blood pressure, headache, nausea, vomiting, muscle and joint pain, and a metallic taste in the mouth, with the majority of reactions being complement activation–related pseudo-allergy (infusion reactions) rather than true anaphylaxis 1.

Common Side Effects

• Temporary low blood pressure
• Headache
• Nausea
• Vomiting
• Muscle and joint pain
• Metallic taste in the mouth

Serious but Less Common Reactions

• Allergic responses, ranging from mild itching and rash to severe anaphylaxis, which typically occur during or shortly after administration
• Elderly patients may be particularly susceptible to hypotension during infusion and may experience dizziness or falls as a result
• Delayed reactions 24-48 hours after treatment, including fever, muscle aches, and joint pain
• Iron overload, a rare but serious concern, especially with multiple infusions

Formulation-Specific Side Effects

• The specific formulation used, such as iron sucrose, ferric carboxymaltose, or iron dextran, affects the side effect profile, with iron dextran carrying higher allergic reaction risks 1

Monitoring and Precautions

• Elderly patients should be monitored closely during and after infusions due to their potentially reduced ability to compensate for cardiovascular changes and greater susceptibility to adverse effects
• True anaphylaxis is very rare, and the vast majority of reactions to intravenous iron are complement activation–related pseudo-allergy (infusion reactions) and should be treated as such 1

From the FDA Drug Label

The following clinically significant adverse reactions are described elsewhere in the labeling: Hypersensitivity Reactions [see Warnings and Precautions ( 5.1)] Hypotension [see Warnings and Precautions ( 5.2)] Iron Overload [see Warnings and Precautions ( 5.3)] The most common adverse reactions (>2% of patients) in all patients were headache (6%), respiratory tract viral infection (4%), peritonitis (4%), vomiting (4%), pyrexia (4%), dizziness (4%), cough (4%), nausea (3%), arteriovenous fistula thrombosis (2%), hypotension (2%), and hypertension (2.1%). Symptoms associated with Venofer total dosage or infusing too rapidly included hypotension, dyspnea, headache, vomiting, nausea, dizziness, joint aches, paresthesia, abdominal and muscle pain, edema, and cardiovascular collapse

The side effects of an iron infusion for an 86-year-old may include:

• Hypersensitivity reactions
• Hypotension
• Iron overload
• Headache
• Dizziness
• Nausea
• Vomiting
• Joint aches
• Paresthesia
• Abdominal and muscle pain
• Edema
• Cardiovascular collapse 2

From the Research

Side Effects of Iron Infusion

The side effects of an iron infusion for an 86-year-old patient can be understood by examining the available evidence on iron infusion therapy.

• Severe infusion reactions are a risk associated with all iron preparations, although the risk is relatively low, affecting less than 1% of patients 3.
• Hypophosphatemia, or the 6H syndrome, is an emerging complication that can affect 50-74% of patients treated with ferric carboxymaltose, leading to severe and potentially irreversible clinical complications such as bone pain, osteomalacia, and fractures 3.
• Other potential side effects of iron infusion include nausea, reduced blood pressure, vomiting, dysgeusia, constipation, fatigue, and anxiety, although these are generally mild and uncommon 4, 5.
• Serious allergic reactions to iron infusion are rare, with one study reporting only one serious allergic reaction out of 2,468 patients 6.
• There are also concerns about the long-term safety of intravenous iron, including the potential for oxidative stress, kidney injury, and accelerated atherosclerosis 7.

Patient-Specific Considerations

When considering iron infusion therapy for an 86-year-old patient, it is essential to weigh the potential benefits against the potential risks and to carefully monitor the patient for any adverse effects.

• The patient's overall health status, medical history, and current medications should be taken into account when determining the appropriateness of iron infusion therapy.
• The choice of iron preparation and dosing regimen should be individualized based on the patient's specific needs and medical status.
• Close monitoring of the patient's hemoglobin, ferritin, and other relevant laboratory values is necessary to assess the effectiveness of the therapy and to minimize the risk of adverse effects.