What are the side effects of iron sucrose (Intravenous Iron) and how can they be managed?

Iron Sucrose Side Effects and Management

Iron sucrose is generally well-tolerated with an approximate 0.5% incidence of hypersensitivity-type and infusion reactions, significantly lower than iron dextran, though more common than oral iron preparations. 1

Common Side Effects

Mild to Moderate Adverse Events

• Metallic taste occurs in approximately 18% of administrations but is transient and causes no significant distress 2
• Hypotension, nausea, vomiting, and diarrhea are the most frequently reported systemic effects 1
• Pain at injection site (during or after administration), headache, dizziness, and pruritus occur in approximately 2.5% of injections 2, 3
• Arthralgia and myalgia have been documented, with arthralgia being a notable side effect in observational studies 4, 5
• Flushing and abdominal cramps may occur during infusion 4

Serious Adverse Events

• Anaphylactoid reactions occur in approximately 0.3% of administrations (7 reactions in 2,297 injections in one large prospective study), all resolving within 30 minutes without hospitalization 2
• Symptoms of severe reactions include dyspnea, wheezing, hypotension, and chest pain 1, 3
• Systemic iron toxicity with hepatocellular damage has been reported when doses exceed recommended maximums (>16 mg/kg in pediatric case) 1

Metabolic Complications

• Hypophosphataemia occurs in approximately 1% of iron sucrose patients (compared to 58% with ferric carboxymaltose and 4% with iron derisomaltose) 1
• Most episodes are biochemically moderate (serum phosphate 0.32-0.64 mmol/L), asymptomatic, and resolve spontaneously 1

Safety Profile Compared to Other IV Iron Preparations

Iron sucrose has fewer adverse effects than iron dextran formulations, particularly high molecular weight iron dextran. 1

• Iron sucrose demonstrated safe administration in 130 hemodialysis patients previously intolerant to iron dextran and/or ferric gluconate, with no serious adverse events 6
• Side effect frequency between low molecular weight iron dextran and iron sucrose was similar (11/30 vs 13/30 patients) in head-to-head comparison 3
• Serious adverse reaction rates are low and similar between oral and parenteral iron preparations overall 1

Management Strategies

Pre-Administration Precautions

• Test doses are recommended (though not required) for patients with history of IV iron sensitivities or multiple drug allergies 1, 4
• Resuscitation facilities must be available during administration due to anaphylaxis risk 4
• Withhold iron sucrose in patients with active bacteremia, though infection is not an absolute contraindication if risk/benefit favors treatment 1

During Infusion Monitoring

• Monitor vital signs during and after infusion to detect potential reactions 4
• Start infusion slowly for the first 5 minutes to monitor for reactions 4
• Consider alternative approach: administer 25 mg test dose over 5 minutes, wait, then continue with remainder 4

Managing Infusion Reactions

• Stop the infusion immediately if minor reactions occur 4
• Switch to hydration fluid to keep vein open and continue monitoring 4
• Most reactions are self-limiting and resolve spontaneously with continued monitoring until symptom resolution 4
• After 15 minutes, rechallenge may be considered with careful monitoring if symptoms have resolved 4
• Administer IV corticosteroid (such as hydrocortisone) if symptoms do not improve or worsen after 15 minutes 4

Dosing Considerations to Minimize Risk

• Maximum single dose is 200 mg with maximum weekly dose of 500 mg 4
• Doses exceeding recommended maximums increase risk of serious adverse events 1
• Iron sucrose can be safely administered as 2-minute bolus injection (200 mg) or 30-minute infusion, both with similar safety profiles 4, 2

Special Populations

Pediatric Patients

• Very few serious adverse reactions observed in 232 children receiving 1,624 doses 1
• Only one adverse event (skin rash) considered drug-related in randomized study of 145 children/adolescents 1
• The single significant reaction occurred when dose exceeded recommended maximum of 300 mg 1

Patients with Collagen Diseases

• Increased incidence of adverse effects has been reported in this population 1

Key Clinical Pitfalls to Avoid

• Do not administer during active infection, particularly bacteremia, though chronic infection alone is not an absolute contraindication 1
• Avoid exceeding maximum single dose of 200 mg to minimize dose-related anaphylactoid reactions 1, 4
• Do not assume test doses eliminate all risk - anaphylactoid reactions can still occur even after negative test doses 1
• Monitor serum phosphate in patients receiving long-term or multiple high-dose infusions if risk factors for hypophosphataemia exist 1