An intravenous (IV) iron infusion delivers iron directly into the bloodstream. This treatment is used for individuals with severe iron deficiency or anemia who cannot absorb enough iron from oral supplements or when oral supplements have failed. The rapid delivery helps quickly replenish iron stores and supports the production of hemoglobin, the protein in red blood cells that carries oxygen. Common formulations used include iron sucrose (Venofer) and ferumoxytol (Feraheme).
Iron infusions generally do not cause a visible change in urine color. When the iron compound is infused, it is quickly processed by the body. The iron is encapsulated and rapidly bound to transport proteins like transferrin or stored within cells as ferritin.
This efficient process means that very little free iron is available to be filtered by the kidneys and excreted in the urine. The amount of iron lost through the urine is minimal, insufficient to cause noticeable discoloration. If a patient observes dark or discolored urine after the procedure, it is likely due to a separate issue, such as concentrated urine from dehydration, the presence of blood (hematuria), or a reaction leading to red blood cell breakdown (hemolysis).
Common Visible Side Effects of Iron Infusion
Patients should be aware of several common and visible reactions. The most frequent physical side effect is skin staining, or discoloration, at the infusion site. This occurs if the iron solution leaks out of the vein into the surrounding tissue, a process called extravasation.
The extravasated iron can cause a temporary or prolonged brown discoloration of the skin. While this staining is not dangerous, it can be cosmetically concerning and may require specific dermatological treatments. Nurses administering the infusion take steps to prevent this, but the risk exists with any IV procedure.
Another common sensory change is a metallic taste in the mouth during or shortly after the infusion. This taste results from the iron compound circulating in the bloodstream and is short-lived. Patients may also experience flushing or warmth, particularly in the face and chest, as a temporary reaction.
Unlike oral iron supplements, which commonly cause dark, tarry stools, IV iron rarely causes a dramatic change in stool color. Since the iron is delivered directly into the bloodstream, the high concentration of unabsorbed iron in the gut is bypassed. A mild darkening of the stool might be observed, but it is less pronounced than with oral supplements.
Recognizing Serious Post-Infusion Symptoms
While most side effects are mild and temporary, patients must recognize signs of a severe reaction, which require immediate medical attention. These serious symptoms often indicate a hypersensitivity reaction or anaphylaxis, a life-threatening, whole-body allergic response. Symptoms usually occur during the infusion or within the first few hours afterward.
Signs of a severe systemic reaction include sudden trouble breathing, tightness in the chest, and swelling of the face, throat, or tongue. Other signs include a widespread rash or hives, severe dizziness, rapid drop in blood pressure, rapid heartbeat, or chest pain.
Patients must immediately alert the healthcare provider or nurse if any severe symptoms develop during the procedure. If a patient is at home and experiences signs of a severe reaction, such as difficulty breathing or swelling, they should seek emergency medical services right away. Persistent high fever or signs of infection at the infusion site, like increasing redness, warmth, or discharge days after the procedure, should also be reported promptly.