English Summary
CHOLESTEROL, HYPERCHOLES-
TEROLEMIA AND THE DRUGS
AGAINST IT. A REVIEW.
Abraham Simatupang
Department of Pharmacology- School of
Medicine Christian University of Indonesia.
Jakarta, Indonesia
Lipoproteins (macromolecular
complexes of lipid and proteins)
transport lipids and cholesterol
through the blood stream. Such a
transport system is essential to life
since these lipid materials are
needed for cell growth, hormone
production and transmembrane
transport. However, an excess of
one important class of lipopro-
teins known as low density lipo-
protein (LDL) increases the risk of
ischaemic heart disease.
Body cholesterol is derived
from two sources, namely, (1)
endogenous, obtained from
synthesis, which occurs mainly in
the liver with the help of an key
enzyme HMG-CoA reductase.
and (2) dietary cholesterol
absorbed from the intestine.
Cholesterol are degraded to bile
acids, a process which is cata-
lysed with 7-hydroxylase, or it
will be secreted as cholesterol by
biliary secretion and faecal loss.
National Education Program
Coordinating Committee classi-
fies serum cholesterol level 200
mg/dL as "desirable blood cho-
lesterol", 200-239 mg/dL as
"borderline high blood choles-
terol", and above 240 mg/dL as
"high blood cholesterol". The diet
therapy is still the first attempt
that people should consider in
reducing hypercholesterolemia.
The dietary therapy should con-
sistof at least 4 principles,namely
(1) reduction of fat intake, maxi-
mum up to 30% of total intake of
calory by reducing the intake of
saturated fatty acids to 10%
of total energy, (2) increasing
dietary intake of mono and poly-
unsaturated fats. Ten to 15% per-
cent of consumed energy should
be supplied in form of mono-
and 7 to 10% of polyunsaturated
fats, (3) increasing dietary intake
of complex carbohydrates and
fiber, (4) reduction of cholesterol
intake ( 300 mg/day). Patients
who do not respond appropria-
tely to dietary therapy should be
given lipid-lowering drugs. In
making the decision to start drug
therapy, it should be considered
that the treatment will probably
be a life-long therapy. A wide
range of lipid-lowering drugs are
available nowadays.
Cholestyramine and colestippl
which belong to bile-acid se-
questrant resins bind bile acids
in the intestinelandireduce their
enterohepatic circulation there-
by stimulating their faecal loss.
Nicotinic acid inhibits, by un-
known mechanism, the produc-
tion of VLDL particles from the
liver, leading to low VLDL-trigly-
ceride. concentrations and low
levels of LDL-C in serum. This drug
increases also HDL-C. Estrogen is
nowadays administered either as
adjunction or as main therapy to
the postmenopausal women.
while the risk of CHD is increased
due to sinking level of estrogen in
the body.
Recently, a group of lipid-
lowering drugs called statins had
been proven to show a promising
effect either through small group
or population-based studies.
These drugs compefitively inhibit
HMG-CoA reductase, the rate
limiting enzyme in the biosynthe-
sis of cholesterol leading to
increased expression of LDL re-
ceptors. However, the mecha-
nism of action of these drugs is
more complex than the original
concept. Pravastatin, simvastatin
and fluvastatin are now available
in the dispensaries. Pravastatin,
which is more hydrophilic than
simvastatin and fluvastatin, is
Implied more selective than the
latter. It can be suggested, there-
fore, that pravastatin also reduces
the synthesis of cholesterol in extra
hepatic tissues.
With the availability of new
pharmacological agents, an
effective treatment of the
common forms of hyperlipo-
proteinemia is now possible,
Cermin Dunia Kedokt. 1997; 116:5-12
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(Bersambung ke halaman 32 dan 61)
Cermin Dunia Kedokteran No. 116, 1997
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