Usage
Dextran 40 + Dextrose is prescribed for hypovolemic shock resulting from hemorrhage, burns, surgery, or trauma. It is also used for prophylaxis against venous thrombosis and pulmonary embolism in high-risk surgical procedures like hip surgery. It is administered intravenously and is classified as a plasma volume expander and combined with a nutrient replenisher, providing both volume expansion and a source of energy.
Dextran 40 exerts its effects by expanding plasma volume. It increases the osmotic pressure within the intravascular space, which draws fluid from the interstitial space into the bloodstream, thereby expanding the circulating blood volume. Dextrose provides a source of calories and hydration.
Alternate Names
Dextran 40 is also known as Low Molecular Weight Dextran (LMD), while the combination with Dextrose is sometimes referred to as “Dextran 40 in 5% Dextrose”. Brand names include Dextran 40, Gentran 40, LMD, Rheomacrodex.
How It Works
Pharmacodynamics: Dextran 40 increases the colloid osmotic pressure of the blood, leading to an expansion of plasma volume. This is particularly useful in hypovolemic shock where blood volume is significantly reduced. Dextrose contributes as a carbohydrate source, providing energy.
Pharmacokinetics: Dextran 40, when administered intravenously, reaches peak plasma volume expansion almost immediately after infusion. The duration and extent of volume expansion depend on the infused volume, the patient’s pre-infusion plasma volume, and the rate of renal clearance. It is excreted primarily through the kidneys. Dextrose is rapidly metabolized to provide energy.
Mode of Action: Dextran 40 works by drawing fluid from the interstitial space into the intravascular compartment. This expands the circulating blood volume, improving blood flow to vital organs. There is no specific receptor binding, enzyme inhibition or neurotransmitter modulation involved in its action. Dextrose is directly metabolized by cells for energy production.
Elimination Pathways: Dextran 40 is primarily eliminated through renal excretion. A smaller portion may be metabolized or excreted through other pathways. Dextrose is primarily metabolized by cells.
Dosage
Standard Dosage
Adults:
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Shock: Initial dose: 10 mL/kg (1 g/kg) IV as rapid infusion. Maximum dose during the first 24 hours: 20 mL/kg (2 g/kg). Subsequent doses (if treatment continues beyond 24 hours): Not to exceed 10 mL/kg/day for up to 5 days.
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Prophylaxis of venous thrombosis/thromboembolism: 500–1000 mL (approximately 10 mL/kg) IV infusion on the day of surgery. Continue with 500 mL daily for 2-3 days, then 500 mL every 2–3 days for up to 2 weeks depending on the risk.
Children:
- Infants: 0.5 g/kg (5 mL/kg).
- Children: 1 g/kg (10 mL/kg).
- Adolescents: Initial dose in thromboembolic prophylaxis is the same as adults but adjusted according to thromboembolic risk (e.g. surgery type, immobilization period).
Special Cases:
- Elderly Patients: Dose adjustments might be necessary based on cardiac and renal function. Careful monitoring of fluid status is crucial.
- Patients with Renal Impairment: Dextran 40 should be used with extreme caution. Dose reductions are generally recommended.
- Patients with Hepatic Dysfunction: Dextran 40 should be used with extreme caution due to potential impacts on coagulation.
- Patients with Comorbid Conditions: Use cautiously in patients with cardiac decompensation or diabetes.
Clinical Use Cases
Dosages are similar to standard dosages, adjusting based on patient condition and fluid status.
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Intubation: Facilitates fluid administration when IV access is limited.
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Surgical Procedures: Prophylaxis and treatment of hypovolemic shock.
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Mechanical Ventilation: Supports fluid management in critically ill patients.
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Intensive Care Unit (ICU) Use: Essential in managing severe hypovolemia.
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Emergency Situations: Rapid volume expansion in cases of hemorrhage or severe shock.
Dosage Adjustments:
Dosages should be adjusted based on patient-specific factors, such as renal/hepatic function, other existing medical conditions, and response to therapy.
Side Effects
Common Side Effects:
Nausea, vomiting, mild urticaria, joint pain, fever.
Rare but Serious Side Effects:
Anaphylaxis or anaphylactoid reactions (DIAR), acute renal failure, bleeding complications, pulmonary edema, hypotension.
Long-Term Effects:
Data regarding the long-term effects of Dextran 40 is limited. Prolonged use may be associated with increased risk of bleeding and renal dysfunction.
Adverse Drug Reactions (ADR):
Anaphylaxis, severe hypotension, renal failure, bleeding diathesis.
Contraindications
Hypersensitivity to dextran, marked cardiac decompensation, severe renal failure with oliguria or anuria, significant bleeding disorders (e.g., thrombocytopenia), extreme dehydration.
Drug Interactions
Additive medications should not be administered through the same IV line as Dextran 40. Enhanced effects of anticoagulants (like heparin or warfarin) might be observed. Dextran can interfere with some laboratory tests (blood typing, bilirubin, blood sugar). Monitor for interactions with drugs that affect renal function or increase bleeding risk.
Pregnancy and Breastfeeding
Pregnancy Safety Category: C. There are no adequate and well-controlled studies in pregnant women. Use only if the potential benefit justifies the potential risk to the fetus. It is unknown whether this drug is excreted in human milk. Caution is advised when administering to nursing mothers.
Drug Profile Summary
- Mechanism of Action: Plasma volume expander.
- Side Effects: Nausea, vomiting, hypotension, anaphylaxis, bleeding.
- Contraindications: Hypersensitivity, cardiac decompensation, renal failure, bleeding disorders.
- Drug Interactions: Anticoagulants, certain lab tests.
- Pregnancy & Breastfeeding: Category C; caution advised.
- Dosage: Varies based on indication and patient characteristics.
- Monitoring Parameters: Vital signs, renal function, bleeding time, urine output, central venous pressure (if applicable).
Popular Combinations
Dextran 40 is not typically used in fixed combinations with other drugs but may be administered concurrently with crystalloid solutions or other medications for managing shock and its complications.
Precautions
Carefully monitor patients for fluid overload, especially those with cardiac or renal dysfunction. Screen for dextran hypersensitivity prior to administration. Observe for signs of bleeding, especially in patients receiving high doses or with pre-existing coagulopathies. Adjust dosage in renal/hepatic impairment. Use cautiously in elderly patients.
FAQs (Frequently Asked Questions)
A: The dosage varies significantly depending on the indication (shock, thromboembolism prophylaxis), patient age, weight, and clinical condition. See detailed dosage guidelines above.
A: It expands plasma volume by increasing colloid osmotic pressure.
A: Hypersensitivity to dextran, severe heart failure, renal failure, severe bleeding disorders.
A: Pregnancy category C. Use cautiously and only if clearly needed, as safety in pregnancy has not been established.
A: Nausea, vomiting, mild allergic reactions, joint pain, fever.
Q6: How is Dextran 40 eliminated from the body?
A: Primarily through renal excretion.
A: Possible interaction with anticoagulants, increasing the risk of bleeding.
A: Monitor for fluid overload, bleeding complications, and allergic reactions. Careful dose adjustment needed in patients with renal/hepatic impairment.
A: Yes, dosage guidelines are available for infants, children and adolescents.
A: Monitor vital signs, urine output, bleeding time, and signs of fluid overload or allergic reactions. Renal function tests may be necessary.
