1. Clinical Overview
Iron Sucrose is a parenteral iron preparation consisting of a polynuclear iron(III)-hydroxide core stabilized by a sucrose shell, forming a complex with a molecular weight of approximately 34,000–60,000 Da. It is used for the rapid correction of iron deficiency anemia (IDA) in patients where oral iron is ineffective, not tolerated, or where a rapid replenishment of iron stores is clinically required. It is a colloidal solution for intravenous administration.
| Onset | Duration | Bioavailability |
|---|---|---|
| Reticulocyte count begins to increase within 3-7 days. Hemoglobin levels typically start rising within 1-2 weeks. | The duration of effect is prolonged, as it replenishes iron stores (ferritin). The effect on hemoglobin can last for several months, depending on the underlying cause of anemia. | 100% when administered intravenously. |
2. Mechanism of Action
Iron Sucrose delivers bioavailable iron directly into the intravascular space, bypassing the gastrointestinal absorption barrier. The complex is designed to be stable, minimizing the release of free, toxic ionic iron into the circulation. It is phagocytosed by macrophages of the reticuloendothelial system (RES). Within the macrophages, the sucrose ligand is enzymatically cleaved, releasing iron into the intracellular labile iron pool. This iron is then either stored as ferritin or released into the plasma bound to transferrin, the physiological iron transport protein. Transferrin-bound iron is delivered to erythroid precursor cells in the bone marrow for incorporation into hemoglobin.
3. Indications & Uses
- Iron Deficiency Anemia (IDA) in patients with chronic kidney disease (CKD), both non-dialysis dependent (NDD-CKD) and dialysis dependent (DD-CKD).
- Iron Deficiency Anemia in patients with inflammatory bowel disease (IBD) where oral iron is ineffective/not tolerated.
- Iron Deficiency Anemia in postpartum women with significant blood loss.
- Iron Deficiency Anemia associated with heavy uterine bleeding (menorrhagia).
4. Dosage & Administration
Adult Dosage: Dose is calculated based on body weight and hemoglobin deficit. Formula: Total iron deficit (mg) = Body weight (kg) x (Target Hb - Actual Hb) (g/dL) x 2.4 + Iron stores (500 mg). For simple iron deficiency, a common regimen is 100-200 mg (5-10 ml) per dose, administered 1-3 times per week until the total cumulative dose is reached. Maximum single dose: 200 mg (10 ml). Maximum weekly dose: 600 mg.
Administration: For IV Injection (Slow): 100-200 mg (5-10 ml) undiluted, administered at a rate of 1 ml (20 mg) per minute. For IV Infusion: Dilute 100-500 mg (5-25 ml) in a maximum of 250 ml of 0.9% Sodium Chloride. Infuse over at least 15 minutes (for 100 mg) to 3.5-4 hours (for 500 mg). Do not mix with other medications or parenteral nutrition solutions. Observe patient for at least 30 minutes after administration for hypersensitivity reactions.
5. Side Effects
Common side effects may include:
- Metallic taste
- Transient hypotension or hypertension
- Headache
- Nausea
- Injection site reactions (pain, phlebitis, discoloration)
- Flushing
- Dizziness
6. Drug Interactions
| Drug | Effect | Severity |
|---|---|---|
| Oral Iron Supplements | Concurrent use is unnecessary and may increase risk of gastrointestinal side effects without added benefit. | Moderate |
| Angiotensin-Converting Enzyme (ACE) Inhibitors (e.g., Enalapril, Ramipril) | May potentiate the risk of systemic reactions to parenteral iron. | Moderate |
| Dimercaprol | Chelating agent; may form a toxic complex with iron. Contraindicated in iron overload from parenteral iron. | Major |
| Chloramphenicol | May delay the hematologic response to iron therapy by inhibiting erythroid maturation. | Moderate |
7. Patient Counselling
- Do report any history of allergies, asthma, or eczema to your doctor before therapy.
- Do inform your doctor if you are pregnant, planning pregnancy, or breastfeeding.
- Do remain seated or lying down for 30 minutes after the infusion as dizziness can occur.
- Don't take oral iron supplements during the course of injections unless advised by your doctor.
- Don't miss follow-up blood tests (Hb, Ferritin) to monitor response.
8. Toxicology & Storage
Overdose: Acute overdose can lead to hemosiderosis. Symptoms of excess free iron (if complex saturates clearance mechanisms): Nausea, vomiting, abdominal pain, diarrhea, hypotension, tachycardia, lethargy, cyanosis, coma, and signs of shock.
Storage: Store below 25°C. Do not freeze. Keep in original carton to protect from light. The solution is a dark brown, sterile, colloidal liquid. Do not use if the solution is cloudy or contains visible particulate matter. Once the vial is opened, use immediately. Discard any unused portion.