Elephant specific information, if available, is in blue.

Note: Dextran is also available as Dextran 40 and Dextran 75. Because Dextran 70 is the most commonly version used in veterinary medicine, the following monograph is limited to it alone.

Chemistry – A branched polysaccharide used intravenously as a plasma volume expander, dextran 70 occurs as a white to light yellow amorphous powder. It is freely soluble in water and insoluble in alcohol. Dextran 70 contains (on average) molecules of 70,000 daltons. Each 500 ml of the commercially available 6% dextran 70 in normal saline provides 77 mEq of sodium.

Storage/Stability/Compatibility – Dextran 70 injection should be stored at room temperature; preferably in an area with little temperature variability. While only clear solutions should be used, dextran flakes can form but can be resolubolized by heating the solution in a boiling water bath until clear, or autoclaving at 110°C for 15 minutes. Dextran 70 is compatible with many other solutions and drugs; refer to specialized references (e.g. Trissel) for more information.

Pharmacology – Dextran 70 has osmotic effects similarly to albumin. Dextran’s colloidal osmotic effect draws fluid into the vascular system from the interstitial spaces, resulting in increased circulating blood volume.

Uses/Indications – Dextran 70 is a relatively low cost colloid for the adjunctive treatment of hypovolemic shock.

Pharmacokinetics –  After IV infusion, circulating blood volume is increased maximally within one hour and effects can persist for 24 hours or more. Approximately 20-30% of a given dose remains in the intravascular compartment at 24 hours and it may be detected in the blood 4-6 weeks after dosing. Dextran 70 is slowly degraded to glucose by dextranase in the spleen and then metabolized to carbon dioxide and water. A small amount may be excreted directly into the gut and eliminated in the feces.

Contraindications/Precautions/Reproductive Safety – Patients overly susceptible to circulatory overload (severe heart or renal failure) should receive dextran 70 with great caution. Dextran 70 is contraindicated in patients with severe coagulopathies and should be used with caution in patients with thrombocytopenia as it can interfere with platelet function. Do not give dextran IM. Patients on strict sodium restriction should receive dextran cautiously as a 500 ml bag contains 77 mEq of sodium

Adverse Effects/Warnings – Moderate to life threatening reactions appear to rare in the dog. Dextran 70 may increase bleeding time and decrease von Willebrand’s factor antigen and factor VIII activity. This apparently does not usually cause clinical bleeding in dogs. Anaphylactoid reactions are not that rare in humans, but apparently are very rare in dogs. Dextran 70 has only been rarely associated with acute renal failure, unlike dextran 40. In hu­mans, GI effects (abdominal pain, nausea/vomiting) have been reported with use of dextran 70.

Overdosage – The drug should be dosed and monitored carefully as volume overload may result.

Drug Interactions – Dextran reportedly has no drug interactions that are clinically significant.

Lab Interactions – Dextran 70 may interfere with blood cross-matching as it can cross-link with red blood cells and appear as rouleaux formation. Isotonic saline may be used to negate this effect. Blood glucose levels may be increased as dextran is degraded. Falsely elevated bilirubin levels may be noted; reason unknown.

Doses –

Dogs:

a) Up to 40 ml/kg/day; not to be infused faster than 5 ml/kg/hr (Haskins 1992)

b) 20 ml/kg; bolus to effect (Eastlake and Snyder 1998)

Monitoring Parameters – Other than the regular monitoring performed in patients that would require volume expansion therapy, there is no inordinate monitoring required specific to dextran therapy.

Dosage Forms/Preparations/FDA Approval Status –

Veterinary-Approved Products: None

Human-Approved Products:

6% Dextran-70 in normal saline (0.9% NaCl) in 500 ml; Dextran 70 (McGaw); Gentran® 70 (Baxter) Macrodex® (Medisan); (Rx)

6% Dextran-70 in D5W in 500 ml; Macrodex® (Medisan); (Rx)