hetastarch (HES, hydroxyethyl starch)
Hespan

Available forms
Available by prescription only
Injection: 500 ml (6 g/100 ml in normal saline solution)

Indications and dosages
 Plasma expander in shock and cardiopulmonary bypass surgery. Adults: 500 to 1,000 ml I.V. dependent on amount of blood lost and resultant hemoconcentration. Total dose usually shouldn’t exceed 20 ml/kg, up to 1,500 ml daily. Up to 20 ml/kg (1.2 g/kg)/hour may be used in hemorrhagic shock; in burns or septic shock, rate should be reduced.
 Leukapheresis adjunct.  Hetastarch is an adjunct in leukapheresis to improve harvesting and increase the yield of granulocytes.
Adults: Hetastarch 250 to 700 ml is infused at a constant fixed ratio, usually 1:8 to venous whole blood during continuous flow centrifugation (CFC) procedures. Up to 2 CFC procedures weekly, with total of 7 to 10 procedures using hetastarch, have been found safe and effective. Safety of larger numbers of procedures is unknown.
 Note: Hetastarch can be used as a priming fluid in pump oxygenators for perfusion during extracorporeal circulation or as a cryoprotective agent for long-term storage of whole blood.

Pharmacodynamics
Plasma volume expanding action: Hetastarch has an average molecular weight of 450,000 and exhibits colloidal properties similar to human albumin. After an I.V. infusion of hetastarch 6%, the plasma volume expands slightly in excess of the volume infused because of the colloidal osmotic effect. Maximum plasma volume expansion occurs in a few minutes and decreases over 24 to 36 hours. Hemodynamic status may improve for 24 hours or longer.
Leukapheresis adjunctive action: Hetastarch enhances yield of granulocytes obtained by centrifugal means.

Pharmacokinetics
Absorption: Administered I.V.
Distribution: Distributed in blood plasma.
Metabolism: Hetastarch molecules larger than 50,000 molecular weight are slowly enzymatically degraded to molecules that can be excreted.
Excretion: 40% of hetastarch molecules smaller than 50,000 molecular weight are excreted in urine within 24 hours. Hetastarch molecules that aren’t hydroxyethylated are slowly degraded to glucose. About 90% of dose is eliminated from the body with an average half-life of 17 days; remainder has a half-life of 48 days.

Contraindications and precautions
Contraindicated in patients with severe bleeding disorders, severe heart failure, or renal failure with oliguria and anuria.

Interactions
None reported.

Adverse reactions
CNS: headache, mild fever.
CV: peripheral edema of the legs.
EENT: periorbital edema.
GI: nausea, vomiting.
Musculoskeletal: muscle pain.
Respiratory: wheezing.
Skin: urticaria, itching.
Other: chills, parotid and submaxillary gland enlargement.

Effects on lab test results
None reported.

Overdose and treatment
Signs and symptoms of overdose include the adverse reactions listed above.
 Stop infusion if an overdose occurs, and treat supportively.

Special considerations
• When added to whole blood, hetastarch increases the erythrocyte sedimentation rate.
• Don’t administer as a substitute for blood or plasma.
• Discard partially used bottle because it doesn’t contain a preservative.
• Monitor I.V. site for signs of infiltration and phlebitis.
• To avoid circulatory overload, carefully monitor patients with impaired renal function and those at high risk of pulmonary edema or heart failure. Hetastarch 6% in normal saline solution contains 77 mEq sodium and chloride per 500 ml.
• Monitor CBC, total leukocyte and platelet counts, leukocyte differential count, hemoglobin, hematocrit, PT, PTT, and electrolyte, BUN, and creatinine levels.
• Assess vital signs and cardiopulmonary status to obtain baseline at start of infusion to monitor for fluid overload.
Pregnant patients
• Don’t use hetastarch in pregnant women, especially during early pregnancy. Use drug only when benefit to mother outweighs risk to fetus.
Breast-feeding patients
• Women receiving hetastarch should temporarily discontinue breast-feeding.
Pediatric patients
• Safety and efficacy in children haven’t been established.
Geriatric patients
• Use hetastarch cautiously in elderly patients because of the risk of fluid overload; a lower dosage may be sufficient to produce desired plasma volume expansion.

Patient education
• Explain use and administration of drug to patient and family.
• Instruct patient to report adverse reactions promptly.

Reactions may be common, uncommon, life-threatening, or COMMON AND LIFE THREATENING.
◆ Canada only
◇ Unlabeled clinical use