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
Infed Pharmacology, Pharmacokinetics, Studies, Metabolism - Iron Dextran
Infed Pharmacology, Pharmacokinetics, Studies, Metabolism - Iron Dextran
CLINICAL PHARMACOLOGY
General
After intramuscular
injection, iron
dextran is absorbed
from the injection site into the capillaries and the lymphatic
system. Circulating iron
dextran is removed from the plasma
by cells of the reticuloendothelial
system, which split the
complex into its components
of iron and dextran. The
iron is immediately bound
to the available protein
moieties to form hemosiderin
or ferritin, the physiological
forms of iron, or to a
lesser extent to transferrin. This iron
which is subject to
physiological
control replenishes
hemoglobin and depleted iron
stores.
Dextran, a polyglucose, is either metabolized or excreted. Negligible
amounts of iron are lost
via the urinary
or alimentary pathways
after administration of iron
dextran.
The major portion of intramuscular
injections of iron dextran
is absorbed within 72 hours; most of the remaining iron
is absorbed over the ensuing 3 to 4 weeks.
Various studies involving intravenously administered 59Fe
iron dextran to iron
deficient subjects, some of whom had coexisting diseases, have yielded
half- life values ranging
from 5 hours to more than 20 hours. The 5-hour value
was determined for 59Fe iron
dextran from a study
that used laboratory
methods to separate the circulating 59Fe iron dextran
from the transferrin- bound
59Fe. The 20-hour value reflects a half- life
determined by measuring total 59Fe, both circulating
and bound. It should be understood that these half-life
values do not represent clearance
of iron from the body.
Iron is not easily eliminated from the body
and accumulation of iron
can be toxic.
In vitro studies have shown that removal of iron
dextran by dialysis
is negligible.¹,² Six different dialyzer
membranes were investigated (polysulfone, cuprophane, cellulose
acetate, cellulose triacetate, polymethylmethacrylate and polyacrylonitrile),
including those considered high efficiency and high flux.
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