GENERIC NAME: cholestyramine
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BRAND NAME: Questran, Questran Light
DRUG CLASS AND MECHANISM: Cholestyramine is an oral
medication that reduces the levels of cholesterol in
the blood and improves the itching associated with liver
disease.
Cholesterol that is ingested or manufactured
in the body is eliminated primarily by conversion to
bile acids in the liver and excretion in bile. The bile
enters the intestine, and most of the bile acids are
reabsorbed from the intestine. These reabsorbed bile
acids are removed from the blood by the liver and excreted
again into bile. Thus, bile acids re-circulate in the
body. Cholestyramine binds to bile acids in the intestine.
This prevents their absorption, and the cholestyramine/bile
acid complexes are eliminated in the stool. As a result,
the body loses bile acids. To compensate for this loss,
the liver increases the conversion of cholesterol to
bile acids. The conversion of cholesterol to bile acids
reduces the cholesterol in the body, and the levels
of cholesterol drop in the blood.
One of the most troubling symptoms in patients
with liver and biliary disease is itching. The itching
is believed to be the result of accumulation of bile
acids in the skin due to the inability of the liver
or bile ducts to eliminate bile acids normally. By binding
bile acids in the intestines and preventing their absorption,
cholestyramine hastens the elimination of bile acids
from the body and skin, and the itching improves.
Cholestyramine also binds some drugs in
the intestine, preventing their absorption and hastening
their elimination. Therefore, cholestyramine is useful
in some situations in which there has been an overdose
of drugs.
GENERIC AVAILABLE: yes
PRESCRIPTION: Yes
PREPARATIONS: Powder
STORAGE: Store at room temperature, 15-30°C
(59-86°F)
PRESCRIBED FOR: Cholestyramine is used for
reducing cholesterol levels in the blood, to relieve
the itching of liver and biliary disease, and to treat
overdoses of digoxin or thyroid hormone. Cholestyramine
also is recommended for the rapid elimination of leflunomide
(Arava).
DOSING: The usual dose is 4 to 8 grams once
or twice a day. The maximum dose is 24 grams per day.
Powder should be mixed with 60 to 180 ml (2 to 6 fl
oz) of water, noncarbonated beverage, pulpy fruits or
soup.
DRUG INTERACTIONS: Cholestyramine decreases
the absorption of warfarin (Coumadin), thyroid hormones
(Synthroid, Levoxyl., Liotrix), digoxin (Lanoxin), And
thiazide diuretics (Hydrodiuril, Oretic, Dyazide, Maxide).
Therefore, these drugs should be administered 1 hour
before or 4-6 hours after the administration of cholestyramine.
Cholestyramine decreases the conversion of leflunomide
(Arava) to its active form and reduces the absorption
of vitamin A, D, E and K.
PREGNANCY: Use of cholestyramine in pregnant
women has not been adequately evaluated. Since cholestyramine
is not absorbed into the bloodstream, the risk of adverse
effects on the fetus probably is low.
NURSING MOTHERS: Cholestyramine decreases
the intestinal absorption of vitamins A, D, E and K
by the mother. This could lead to a decrease in the
concentration of these vitamins in the mother's milk
and potentially cause a vitamin deficiency in the infant.
SIDE EFFECTS: The most common side effects
are constipation, abdominal pain, bloating, vomiting,
diarrhea, weight loss, and excessive passage of gas
(flatulence). Long-term use of cholestyramine may cause
a deficiency of vitamin A, D, E, and K.
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