10% LMD in 5% Dextrose Injection(Dextran 40 in Dextrose Injection, USP)10% LMD in 0.9% Sodium Chloride Injection(Dextran 40 in Sodium Chloride Injection, USP)Low Molecular Weight Dextran forIntravenous AdministrationFlexible Plastic ContainerRx onlyDESCRIPTIONLMD (dextran 40) is a sterile, nonpyrogenic preparation of low molecular weightdextran (average mol.wt. 40,000) in 5% Dextrose Injection or 0.9%SodiumChlorideInjection. It is administered byintravenous infusion.Also described as low viscous or low viscosity dextran, dextran 40 is prepared by acid hydrolysis anddifferential fractionation of a crudemacromolecular polysaccharide produced from the fermentation ofsucrose by the bacterium, Leuconostoc mesenteroides(strain B-512). The crude material is composed oflinked glucose units. In the fraction represented bydextran 40, 80% of the molecules have a molecularweight ranging from 10,000 to 90,000 (average approximay 40,000) when measured by a lightscattering method. More than 90% of the linkages are of the 1,6 alpha glucosidic, straight chain type.Each 100 mL of 10% LMD (dextran 40) in 5% Dextrose Injection contains 10 g dextran 40 and 5 gdextrose hydrous in water for injection. Total osmolar concentration is 255 mOsmol/liter (calc.); pH is 4.4(3.0 to 7.0).Each 100 mL of 10% LMD (dextran 40) in 0.9% Sodium Chloride Injection contains 10 g dextran40 and 0.9 g sodium chloride in water for injection. Total osmolar concentration is 310 mOsmol/liter(calc.); pH is 4.9 (3.5 to 7.0) (may contain sodium hydroxide and/or hydrochloric acid for pH adjustment).Electrolyte concentration per liter: Na 154 mEq; Cl ? 154 mEq (not including ions for pH adjustment).The solutions contain no bacteriostat, antimicrobial agent or added bufers (except for pH adjustment)and are intended only for single-dose injection. When smaller doses are required the unused portionshould be discarded.10% LMD (dextran 40) is an artificial colloid pharmacologically classified as a plasma volumeexpander; 5% Dextrose Injection isa fluid and nutrient replenisher; 0.9% Sodium Chloride Injection is aluid and electrolyte replenisher.Dextran 40 is a linear glucose polymer (polysaccharide) chemically designated The structural formula for dextran (repeating unit) is:Dextrose, USP is chemically designated D-glucose monohydrate (C6H12O6• H2O), a hexose sugarfreely soluble in water.Sodium Chloride, USP is chemically designated NaCl, a white crystalline powder freely soluble inwater.Water for Injection, USP is chemically designated H
2O.The flexible plastic container is fabricated from a specially formulatedpolyvinylchloride. Water canpermeate from inside the container into the overwrap but not in amounts sufficient to affect the solutionsignificantly. Solutions inside the plastic container also can leach out certain of the chemical componentsof the plastic in very small amounts before the expiration period is attained. However, safety of the plastichas been confirmed by tests in animals according to USP biological standards for plastic containers.
CLINICAL PHARMACOLOGY
The fundamental action of LMD (dextran 40) is the
enhancement of blood flow, particularly in themicrocirculation. This enhancement is due to:
1. Its primary effect of volume expansion with resultant hemodilution;
2. Maintenance of the electronegativity of red blood cells;
3. Coating of red blood cells and plaets;
4. Increase in the suspension stability of blood;
5. Decrease in the viscosity of blood.
It should be emphasized that the above
effects are not exerted separay,but conjointly they result in theenhancement of blood flow.LMD, used in the treatment of shock, produces significant increases in blood volume, central venouspressure, cardiac output, stroke volume, blood pressure and urinary output. It reduces blood viscosity,
peripheral resistance and improves peripheral blood flowwith the release of sequestered blood cells,thereby increasing venous return to the heart.When used as part of the pump prime for extracorporeal procedures, LMD, as compared to wholeblood, albumin 5%, or whole blood plus 5% dextroseand water, leads to lessdestruction of red bloodcells and plaets, reduces intravascular hemagglutination and maintains erythrocyte electronegativity.
The infusion of LMD (dextran 40) during and after surgical trauma reduces the incidence of deepvenous thrombosis (DVT) and pulmonary embolism (PE) inpatients subject to surgical procedures with ahigh incidence of thromboembolic complication. Unlike antithrombogenic agents of the anticoagulanttype, LMD does not achieve its effect so much byblocking fibrinogen-fibrin conversion but acts bysimultaneously inhibiting other mechanisms essential to thrombus formation such as vascular stasis andplaet adhesiveness and by altering the structure and thereby the lysability of fibrin clots.Histopathological studies have shown that the development of a mural plaet thrombus is the firststage of thrombus formation not only in the arterial, but also in the venous system. A number of studieshave further shown that many patients who develop thromboembolic complicationsshowan abnormallyhigh plaet adhesiveness. Infusion of LMD has been shown to reduceplaet adhesiveness as measuredby variousin vitrotests on blood samples obtained from humansand to inhibit thegrowth of a muralplaet thrombus at the site of experimental (laser beam) injury in the rabbit’s ear chamber.Studies have shown an increase in the lysability of thrombi formed in the presence of dextran. Aconsistent and characteristic alteration in fibrin structure has been observed when fibrin is formed in thepresence of dextran, and further experiments demonstrated such fibrinto be more susceptible to plasmindigestion. Other studies have shown that dextran infused into patients during surgery increases thelysability ofex vivothrombi. Controlled clinical trials have shown that thrombi in patients treated withdextran have a more pronounced tendency to undergo lysis as determined by phlebography.LMD is evenly distributed in the vascular system. Its distribution according to molecular weight shiftstoward higher molecular weights as the smaller molecules are excreted by the kidney. In normovolemicsubjects, approximay 50% is excreted within 3hours, 60% is excreted within 6 hours and about 75%within 24 hours. Reabsorption of dextran by the renaltubules is negligible. The unexcreted molecules ofdextran diffuse into the extravascular compartment and are temporarily taken up by thereticuloendothelial system. Some of these molecules are returned to the intravascular compartment via the
lymphatics. Dextran is slowly degraded
by the enzyme dextranase to glucose.
Solutions containing carbohydrate in the form of
dextrose restore blood gluc
ose levels and provide
calories. Carbohydrate in the form of dextrose may ai
d in minimizing liver glycogen depletion and exerts
a protein sparing action. Dextrose
injected parenterally undergoes ox
idation to carbon dioxide and water.
Sodium chloride in water disso
ciates to provide sodium (Na ) and chloride (Cl ? ) ions. Sodium (Na )
is the principal cation of the extracellular fluid and plays a large part in the therapy of fluid and electrolyte
disturbances. Chloride (Cl ? ) has an integral role
in buffering action when oxygen and carbon dioxide
exchange occurs in red blood cells. The di
stribution and excretion of sodium (Na) and chloride (Cl ? ) are
largely under the control of the kidney, which
maintains a balance betw
een intake and output.
Water is an essential constituent
of all body tissues and accounts for
approximay 70% of total body
weight. Average normal adult daily re
quirement ranges from two to three lite
rs (1.0 to 1.5 liters each for
insensible water loss by pers
piration and urine production).
Water balance is maintained by various regulatory mechanisms. Water distribution depends primarily
on the concentration of electrolytes in the body compartments and sodium (Na
) plays a major role in
maintaining physiologic equilibrium.
INDICATIONS AND USAGE
LMD (dextran 40) is indicated for use in the adjunc
tive treatment of shock or
impending shock due to
hemorrhage, burns, surgery or other trauma. It is no
t indicated as a replacem
ent for whole blood or blood
components if they are available. It
should not replace other forms of th
erapy known to be of value in the
treatment of shock.
LMD is also indicated for use as a priming fluid, either as a sole prime or as an additive, in pump
oxygenators during extracorporeal circulation.
LMD is also indicated for use
in prophylaxis of venous thrombosis and pulmonary embolism in
patients undergoing procedures known
to be associated with a high incidence of thromboembolic
complications, such as hip surgery.
CONTRAINDICATIONS
LMD (dextran 40) is contraindicated in patients with
known hypersensitivity to dextran, in those with
marked hemostatic defects of all types (thrombo
cytopenia, hypofibrinogenem
ia, etc.) including those
caused by drugs (heparin, warfarin, etc.), marked cardi
ac decompensation and in renal disease with severe
oliguria or anuria.
WARNINGS
Although infrequent, severe and fa
tal anaphylactoid reactions consisting of marked hypotension or
cardiac and respiratory arrest have been reported, mo
st of these reactions have
occurred in patients not
previously exposed to intravenous dextran and early in
the infusion period. It is strongly recommended,
therefore, that patients not previously exposed to de