Dextran

Mechanism of Action

Dextran is a polysaccharide produced by bacteria from natural glucose sources, characterized by predominantly α-1,6 glycosidic linkages.[8] Dextran can occur in various molecular weights, such as dextran 40 (40 kDa) and dextran 70 (70 kDa), which are both commonly utilized.[9] As a colloid, dextran osmotically expands plasma volume by restoring blood plasma lost through severe hemorrhage. Its volume of distribution is throughout the blood volume of the body. By expanding blood volume, dextran increases cardiac output and blood flow so red blood cells can effectively circulate to end-organ microvasculature.[1]

Microsurgeons can use dextran to decrease the risk of vascular complications such as thrombosis.[10] This mechanism occurs via the antithrombotic effects of dextran binding to platelets, erythrocytes, and the vascular endothelium to decrease aggregation and adhesiveness.[11] Dextran reduces Von Willebrand factor to decrease the function of platelets.[12]  It also activates plasminogen and prolongs bleeding time. These effects increase proportionally with the increase in the molecular weight of the dextran. 

As an eye lubricant, dextran 70 increases viscosity on the eye's surface to retain tear fluid.[3]

Administration

The most commonly utilized molecular forms for intravenous dextran are dextran 40 and 70.[9] The amount required to treat hemorrhagic shock is administered depending on the amount of blood lost. The prescribing information available online for dextran 40 provides dosing guidance which is paraphrased here: for substantial volume blood loss, between 500 and 1000 mL of a 10% solution may be given as rapidly as necessary; when significant volume losses are not evident or in cases of cardiogenic shock or septic shock, the recommendation is not to give more than 500 mL in one hour; this may be followed by another 500 mL during the ensuing 4 to 8 hours, with a total dose not to exceed 1500 mL in 24 hours in an acute situation.

Technetium Tc99m-labeled dextran, by intravenous administration, is a blood vascular imaging agent for the diagnosis of pericardial effusion, ventricular aneurysms, or bleeds.

Dextran as a formulated component in eye drops will usually be administered 1 to 2 drops at a time.  

Adverse Effects

Adverse effects of dextran are uncommon when administered appropriately. However, allergic reactions—ranging from localized injection site responses to systemic anaphylactic or anaphylactoid events—can occur. Signs such as rash, hives, wheezing, chest tightness, or shortness of breath should alert healthcare providers to the possibility of a serious reaction. In such cases, immediate discontinuation of dextran and emergency management with intravenous fluids, H1 and H2 blockers, epinephrine, and corticosteroids may be required to provide supportive care and prevent airway compromise.[13] Other potential adverse reactions include nausea, vomiting, arthralgias, fevers, and pain. Additional potential adverse effects include nausea, vomiting, arthralgias, fever, and generalized pain. Localized reactions at the injection site may involve venous thrombosis, infection, or febrile responses, making monitoring the site closely throughout treatment essential.

Contraindications

To guard against adverse outcomes, it is important to obtain a careful patient history and review clinical laboratory data before the administration of dextran. It is relatively contraindicated in patients with untreated bleeding disorders, including platelet dysfunction, because of increased bleeding risk. Caution should be exercised in patients with heart failure, as rapid administration may prove dangerous due to the plasma volume expansion effects, potentially leading to circulatory overload and acute decompensation. However, even slower but continued administration may pose some risk as it may reduce plasma protein levels, which can reduce oncotic pressure and worsen edema. If volume overload occurs during dextran administration, an osmotic diuretic is recommended. For patients with underlying renal disease, failure to clear dextran can worsen renal function.[14] Other relative contraindications include severe liver disease, preexisting edema, asthma, diabetes, epilepsy, and seizures.[12][14][15] According to the American College of Cardiology, ACE inhibitors should not be used with the dextran sulfate method due to the risk of bradykinin syndrome.[16]

Monitoring

Because dextran has antithrombotic properties and can prolong bleeding time, careful monitoring of its use is essential.[12] While dextran reduces emboli formation and platelet adhesion, its effects increase proportionally with the molecular weight of the formulation administered. To minimize risks such as excessive wound bleeding, melena, wound seroma, and volume overload, it is important not to exceed the recommended dosage. Additionally, because dextran may impair renal function, clinicians should closely monitor for signs of oliguria or anuria, which may indicate impending renal failure.[14] As elaborated upon previously, monitoring for serious systemic allergic reactions is also crucial.

Toxicity

Renal effects of dextran toxicity are due to the increased serum viscosity, especially in patients with oliguria. A low specific gravity of urine during therapy can suggest a failure of the kidneys to clear dextran, so patients require assessment for hydration during administration and signs of dehydration before the onset of acute renal failure.[14] As previously mentioned, patients with advanced renal disease are especially prone to suffering from worsening renal function. 

Hepatic effects of dextran toxicity may include elevated liver function test results, particularly increased AST and ALT levels, most commonly observed in patients undergoing surgery or cardiac catheterization. This occurs because dextran accumulates in hepatocytes, where it is metabolized; excessive levels can induce hepatic oxidative stress, contributing to liver injury.[15]

Enhancing Healthcare Team Outcomes

The polysaccharide dextran has versatile applications as a colloid in enhancing patient care and improving healthcare team outcomes. It can rapidly replace plasma volume losses in conditions of severe hypovolemia, especially during uncontrolled hemorrhage when compatible whole blood or blood products are not yet available.[1] Furthermore, dextran is also used as an antithrombotic agent, an intravenous radiotracer, and in ophthalmic solutions.[2][3] Adverse reactions to dextran are generally uncommon, largely due to careful monitoring by the interprofessional healthcare team, including clinicians, advanced practitioners, nurses, and pharmacists. When reactions do occur, they may involve cardiac, renal, hepatic, hematologic, or anaphylactic responses. Proactive monitoring for signs of toxicity is essential to enhance patient safety and minimize complications. Achieving this requires coordinated efforts across all disciplines, rather than reliance on a single provider. Collaborative oversight ensures improved therapeutic outcomes with a reduced risk of adverse effects.