Deferoxamine, an iron-chelating agent, was developed in the 1960s and approved for medical use in the 1970s. Its history is marked by its effectiveness in treating acute and chronic iron overload, particularly in patients with thalassemia major and other transfusion-dependent anemias. The drug works by binding excess iron and facilitating its excretion, reducing the risk of organ damage from iron accumulation. While generally effective, Deferoxamine’s subcutaneous or intravenous administration and potential adverse effects, including ototoxicity, visual disturbances, and allergic reactions, required careful monitoring. Its development included protocols for early access in patients with severe iron overload, ensuring close observation for efficacy and safety, and it remains a mainstay in iron chelation therapy, often in combination with other chelators.
BRAND NAMES
Desferal – the most widely used brand for intravenous or subcutaneous administration
Desferal- for Injection – used in hospital settings for acute iron overload.
MECHANISM OF ACTION
Deferoxamine is a high-affinity iron chelator that binds free iron in the blood and tissues, forming a stable complex called ferrioxamine. This complex is water-soluble and is primarily excreted via the urine and, to a lesser extent, bile, allowing the removal of excess iron from the body. By binding free iron, Deferoxamine prevents iron from catalyzing the formation of harmful free radicals, thereby reducing oxidative damage to organs such as the heart, liver, and endocrine glands.
PHARMACOKINETICS
Absorption
Deferoxamine is poorly absorbed orally, which limits its use via the gastrointestinal route. It is therefore administered parenterally, either intravenously (IV) or subcutaneously (SC), to achieve therapeutic systemic concentrations.
Distribution
Deferoxamine has a relatively small volume of distribution (Vd) of approximately 0.2–0.3 L/kg, indicating that it is largely confined to the extracellular fluid rather than extensively distributing into tissues. Its distribution is sufficient to reach plasma and interstitial compartments, where it binds free and loosely bound iron.
Metabolism
Deferoxamine undergoes limited metabolism in the body. Once it binds iron to form the ferrioxamine complex, the complex is mostly excreted unchanged in the urine, with minimal hepatic biotransformation.
Elimination
Deferoxamine is primarily eliminated via the kidneys after binding iron to form the ferrioxamine complex, which is excreted in the urine. A small portion of the drug may also be excreted in bile and feces.
PHARMACODYNAMICS
Deferoxamine acts as a potent iron chelator, selectively binding free and loosely bound iron in the blood and tissues to form a stable, water-soluble complex called ferrioxamine. This chelation prevents iron from participating in Fenton reactions, which generate harmful free radicals that can damage organs such as the heart, liver, and endocrine glands.
ADMINISTRATION
Deferoxamine is administered parenterally, either intravenously (IV), intramuscularly (IM), or subcutaneously (SC), because it is poorly absorbed orally. For acute iron poisoning, it is usually given as a slow IV infusion to achieve rapid chelation and removal of excess iron. For chronic iron overload, such as in transfusion-dependent thalassemia, it is commonly administered subcutaneously via continuous infusion over 8–12 hours, often using a portable infusion pump overnight.
DOSAGE AND STRENGTH
Deferoxamine is available in injectable formulations, typically as vials containing 500 mg or 1 g of deferoxamine mesylate for reconstitution. For acute iron poisoning, the usual dose is 15 mg/kg/hour as a slow intravenous infusion, adjusted based on the severity of toxicity and patient response, with careful monitoring of iron levels and vital signs.
DRUG INTERACTIONS
Deferoxamine can interact with drugs that affect renal function or iron metabolism. Concurrent use with other iron chelators may increase the risk of over-chelation and iron depletion, requiring careful monitoring. Co-administration with aluminum-containing antacids can reduce its efficacy by forming insoluble complexes. Drugs that impair renal function, such as aminoglycosides or cisplatin, may increase the risk of toxicity due to reduced clearance of deferoxamine–iron complexes.
FOOD INTERACTIONS
Deferoxamine has minimal direct food interactions because it is administered parenterally and is not absorbed orally. However, dietary iron intake can influence therapy effectiveness: high dietary iron or oral iron supplements do not interfere significantly with deferoxamine if administered parenterally, but monitoring of iron status is important to guide dosing.
CONTRAINDICATIONS
Deferoxamine is contraindicated in patients with known hypersensitivity to deferoxamine or any component of its formulation. It should not be used in patients with severe renal failure unless the benefits outweigh the risks, as impaired renal function can lead to accumulation of deferoxamine–iron complexes and toxicity.
SIDE EFFECTS
May be mild (e.g., nausea, headache, drowsiness) or severe (e.g., organ damage, allergic reaction).
Can occur immediately or after long-term use.
Can vary between individuals based on age, health, and genetics.
Can be predictable (known from clinical trials) or rare/unexpected.
May require dose adjustment, alternative medication, or discontinuation.
OVER DOSAGE
Overdosage occurs when a person takes more than the recommended dose of a medicine, drug, or other substance. It can happen accidentally, due to misreading instructions, forgetting a previous dose, or intentionally, in cases of self-harm. Overdosage can cause a wide range of symptoms, including nausea, vomiting, dizziness, confusion, seizures, difficulty breathing, and even loss of consciousness.
TOXICITY
Deferoxamine is an iron-chelating drug used to treat iron overload, but excessive use or high doses can lead to toxicity. Acute toxicity is rare but may cause hypotension, allergic reactions, or shock if given too quickly intravenously. Long-term therapy can affect the eyes and ears, leading to visual disturbances, retinal changes, hearing loss, or tinnitus. Other side effects may include fever, rash, nausea, and local reactions at injection sites. Toxicity can be minimized by administering the correct dose, avoiding rapid IV infusion, and monitoring patients’ ocular and auditory function during prolonged treatment.
