Ferric carboxymaltose is a form of iron administered intravenously to treat iron deficiency. It serves as a replacement therapy when the body’s iron stores are low. This method of delivery is an alternative for individuals who cannot use or have not responded to oral iron supplements.
Medical Uses for Ferric Carboxymaltose
Iron deficiency anemia (IDA) occurs when the blood lacks healthy red blood cells due to insufficient iron, which is needed to produce hemoglobin—the substance that carries oxygen. This deficiency can lead to fatigue, weakness, pale skin, and shortness of breath. Ferric carboxymaltose is prescribed to counteract IDA and is also used to improve exercise capacity in certain adults with congestive heart failure.
A healthcare provider may recommend this intravenous iron treatment for several reasons. It is an option for patients who experience significant gastrointestinal side effects, such as nausea or constipation, from taking iron pills. The treatment is also beneficial for individuals whose bodies do not effectively absorb iron from the digestive tract. Certain medical conditions, like inflammatory bowel disease, can interfere with the absorption of oral iron, making IV treatment more effective.
Another use is in situations where iron levels need to be replenished quickly, such as in cases of severe anemia or significant blood loss. This intravenous therapy can raise hemoglobin levels much faster than oral supplements. Patients with chronic kidney disease who are not on dialysis often receive this treatment, as they are frequently unable to maintain adequate iron levels through other means.
The Infusion Procedure
The infusion is a straightforward process performed in a clinical setting, and no special fasting or diet is required beforehand. A healthcare professional inserts a small needle connected to an intravenous line into a vein, usually in the arm or hand. This setup allows the medication to drip directly into the bloodstream.
The infusion itself lasts about 15 minutes. During this time, medical staff monitor the patient and their blood pressure.
After the infusion is complete, the IV line is removed. Patients remain at the clinic for an observation period of at least 30 minutes. Once this period is over and no issues have arisen, the patient can resume their normal activities.
Mechanism of Action
Ferric carboxymaltose is a complex molecule with a ferric hydroxide iron core surrounded by a carbohydrate shell. This stable structure allows a significant amount of iron to be delivered into the body safely. The shell prevents the premature release of large quantities of “free” iron into the bloodstream, which can be toxic.
Once infused, this iron-carbohydrate complex is taken up from the plasma by specialized cells called macrophages, located in the liver, spleen, and bone marrow. These cells internalize the complex and gradually break down the carbohydrate shell. This controlled breakdown releases the iron inside the cells.
The released iron is then either stored within the protein ferritin or transported by the protein transferrin to where it is needed. The primary destination for this iron is the bone marrow. Here, it becomes a building block for the synthesis of hemoglobin, which is then incorporated into new red blood cells.
Potential Side Effects and Reactions
While many people tolerate ferric carboxymaltose well, some may experience side effects. The more common effects are mild and temporary, including headache, dizziness, nausea, and a temporary increase in blood pressure. Some individuals might notice flushing, a change in taste, or a reaction at the injection site, such as pain, swelling, irritation, or a brownish skin discoloration that may be long-lasting.
Although less common, more serious reactions can occur. A severe allergic reaction, including anaphylaxis, requires immediate medical attention. Symptoms can appear during or shortly after the infusion and may include:
- Hives, rash, or itching
- Difficulty breathing or wheezing
- Swelling of the face, tongue, or throat
Medical staff monitor patients for at least 30 minutes post-infusion to manage these reactions promptly.
A notable delayed side effect is symptomatic hypophosphatemia, a condition of having low phosphate levels in the blood. This can develop days or weeks after the infusion. Symptoms to watch for include muscle weakness, bone or joint pain, and fatigue. Patients who experience these symptoms or signs of a severe allergic reaction should contact their doctor without delay.