Desferrioxamine, also known as Desferal, is a medication that removes excess iron from the body. It manages medical conditions where iron levels are dangerously high, preventing harm to organs and tissues.
Understanding Desferrioxamine
Desferrioxamine is classified as an iron-chelating agent. A chelating agent works by binding to substances, like metals, in the body and then helping to remove them. The word “chelation” comes from the Greek word “chele,” meaning “claw,” because the chelating molecule grips the metal atom like a claw.
Desferrioxamine, a natural compound, specifically targets ferric iron (Fe3+), the form of iron commonly found in the body during iron overload. It has three binding sites that securely attach to a single iron ion, forming a stable, water-soluble complex called ferrioxamine. This complex is then excreted from the body, primarily through the kidneys in urine and also via bile in feces. By binding to free iron, desferrioxamine prevents it from causing cellular damage.
Medical Applications
Desferrioxamine is primarily used to treat conditions involving iron overload, where excessive iron accumulation can damage organs. A common scenario is chronic iron overload in patients receiving frequent blood transfusions, such as those with thalassemia or sickle cell disease.
Excess iron can deposit in organs like the liver, heart, and endocrine glands, leading to complications such as liver cirrhosis, heart failure, and diabetes. Desferrioxamine helps reduce this iron burden, protecting these organs from damage. The medication also treats acute iron poisoning, particularly in young children, where iron levels can become toxic and require immediate intervention. In acute poisoning, desferrioxamine should be administered before iron moves into cells and causes systemic toxicity.
Administering Desferrioxamine
Desferrioxamine is not absorbed well orally, so it must be given by injection. The most common routes of administration are subcutaneous (under the skin) or intravenous (into a vein). Subcutaneous infusions are often given slowly over 8 to 12 hours, typically overnight, using a small, portable infusion pump. This method is convenient for patients who can administer the medication at home, usually five to seven times a week, depending on their iron overload.
For patients requiring continuous iron removal or those with severe iron overload, intravenous infusions may be used. In acute iron poisoning or life-threatening situations, intravenous administration is often preferred, with an initial dose of 15 mg/kg per hour, which can be adjusted based on the patient’s response. During treatment, healthcare providers regularly monitor iron levels, often through serum ferritin tests or liver iron concentration measurements, to assess the effectiveness of the medication and make dosage adjustments.
Managing Side Effects
Like all medications, desferrioxamine can cause side effects. Local reactions at the injection site are common with subcutaneous administration, including pain, redness, swelling, itching, or a hard lump. Rotating injection sites and using slow infusions can help minimize these reactions.
Systemic side effects include gastrointestinal issues such as nausea, vomiting, and diarrhea, as well as fever, dizziness, and muscle spasms. More serious, though less common, side effects involve vision and hearing disturbances. Patients may experience blurred vision, poor night vision, difficulty with color perception, ringing in the ears (tinnitus), and hearing loss, particularly at higher frequencies.
These ocular and auditory toxicities are more likely with prolonged use, high doses, or in patients with low iron levels; regular eye and ear examinations are important for early detection. Allergic reactions, including hives, rash, and swelling of the face or throat, can occur. In rare instances, severe reactions like anaphylaxis or low blood pressure may develop, requiring immediate medical attention. Healthcare professionals monitor for these effects and adjust treatment as needed.