Can Venofer (iron sucrose) infusion result in dark-colored urine?

Dark-Colored Urine Following Venofer (Iron Sucrose) Infusion

Venofer (iron sucrose) infusion is not typically associated with dark-colored urine as a common side effect. Based on available guidelines and drug information, dark urine is not listed among the known adverse effects of iron sucrose administration.

Iron Sucrose Pharmacology and Metabolism

• Iron sucrose is an aqueous complex of poly-nuclear iron (III)-hydroxide in sucrose that dissociates into iron and sucrose after intravenous administration 1
• Following administration, the iron component is transported as a complex with transferrin to target cells including erythroid precursor cells, where it is incorporated into hemoglobin 1
• The sucrose component is primarily eliminated through urinary excretion, with approximately 68.3% eliminated in urine within 4 hours and 75.4% within 24 hours 1
• Only about 5% of the iron component is eliminated in urine within 24 hours, which is not sufficient to cause dark coloration 1

Known Adverse Effects of Iron Sucrose

• Iron sucrose has a well-established safety profile with relatively few serious adverse effects compared to other intravenous iron preparations 2

• Common adverse effects include:

  • Hypotension and flushing (rare) 2
  • Abdominal cramps (rare, particularly when co-administered with ACE inhibitors) 2
  • Arthralgias and myalgias (acute rather than delayed) 2

• No reports of dark-colored urine are mentioned in the clinical practice guidelines for anemia management in chronic kidney disease patients receiving iron sucrose 2

Differential Considerations for Dark Urine

If a patient experiences dark-colored urine after iron sucrose infusion, consider these alternative explanations:

• Hemolysis: Some IV iron preparations can rarely cause hemolytic reactions that may result in hemoglobinuria and dark urine 3
• Underlying kidney disease: Patients receiving iron therapy often have kidney dysfunction that may cause urine color changes 2
• Medication interactions: Concomitant medications might interact with iron sucrose or independently cause urine discoloration 2
• Dehydration: Concentrated urine due to dehydration may appear darker 2

Clinical Approach to Dark Urine After Iron Infusion

If dark urine occurs following Venofer administration:

• Assess for signs of hemolysis (decreased hemoglobin, increased bilirubin, LDH) 3
• Evaluate kidney function (creatinine, BUN) 2
• Review medication list for other potential causes of urine discoloration 2
• Ensure adequate hydration status 2

Safety Considerations with Iron Sucrose

• Iron sucrose has one of the better safety profiles among intravenous iron preparations 3, 4
• It does not require a test dose before administration 3
• Doses of 100 mg can be administered over several minutes, and larger doses up to 300 mg can be administered within 60 minutes 3
• Iron sucrose is not associated with the high incidence of life-threatening anaphylactoid reactions seen with some other IV iron preparations 3, 4

Monitoring Recommendations

• Monitor vital signs during and after infusion 2
• Follow hemoglobin, ferritin, and transferrin saturation levels to assess response to therapy 2
• Transferrin and ferritin levels can be measured reliably 48 hours after IV administration 3

In conclusion, while dark-colored urine is not a typical side effect of Venofer administration, if it occurs, further evaluation should be conducted to identify the underlying cause, as it may represent a rare adverse reaction or an unrelated condition.