A1,
A2,
B,
C1,
C2,
D,
E,
F,
G-H,
I-K,
L,
M,
N,
O,
P1,
P2,
Q-R,
S,
T,
U-V,
W-Z
Refludan Online, Description, Chemistry, Ingredients - Lepirudin
Refludan Online, Description, Chemistry, Ingredients - Lepirudin
DESCRIPTION
REFLUDAN [lepirudin (rDNA) for injection] is a highly specific
direct inhibitor of thrombin. Lepirudin (chemical designation: [Leu1,
Thr2]-63-desulfohirudin) is a recombinant hirudin derived from yeast
cells. The polypeptide composed of 65 amino acids has a molecular weight of
6979.5 daltons. Natural hirudin is produced in trace amounts as a family of
highly homologous isopolypeptides by the leech Hirudo medicinalis. The biosynthetic
molecule (lepirudin) is identical to natural hirudin except for substitution
of leucine for isoleucine at the N-terminal end of the molecule and the absence
of a sulfate group on the tyrosine at position 63.
The activity of lepirudin is measured in a chromogenic assay.
One antithrombin unit (ATU) is the amount of lepirudin that neutralizes one
unit of World Health Organization preparation 89/588 of thrombin. The specific
activity of lepirudin is approximately 16,000 ATU/mg. Its mode of action is
independent of antithrombin III. Platelet factor 4 does not inhibit lepirudin.
One molecule of lepirudin binds to one molecule of thrombin and thereby blocks
the thrombogenic activity of thrombin. As a result, all thrombin-dependent coagulation
assays are affected, eg, activated partial thromboplastin time (aPTT) values
increase in a dose-dependent fashion (Roethig 1991).
REFLUDAN is supplied as a sterile, white, freeze-dried powder
for injection or infusion and is freely soluble in Sterile Water for Injection
USP or 0.9% Sodium Chloride Injection USP.
Each vial of REFLUDAN contains 50 mg lepirudin. Other ingredients
are 40 mg mannitol and sodium hydroxide for adjustment of pH to approximately
7.
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