INDICATIONS AND USAGE
1) Cholestyramine for
Oral Suspension USP is indicated as adjunctive therapy to diet for the reduction
of elevated serum cholesterol in patients with primary hypercholesterolemia
(elevated low density lipoprotein [LDL] cholesterol) who do not respond
adequately to diet. Cholestyramine may be useful to lower LDL cholesterol in
patients who also have hypertriglyceridemia, but it is not indicated where
hypertriglyceridemia is the abnormality of most concern.
Therapy with
lipid-altering agents should be a component of multiple risk factor intervention
in those individuals at significantly increased risk for atherosclerotic
vascular disease due to hypercholesterolemia. Treatment should begin and
continue with dietary therapy specific for the type of hyperlipoproteinemia
determined prior to initiation of drug therapy. Excess body weight may be an
important factor and caloric restriction for weight normalization should be
addressed prior to drug therapy in the overweight.
Prior to initiating
therapy with Cholestyramine, secondary causes of hypercholesterolemia (e.g.,
poorly controlled diabetes mellitus, hypothyroidism, nephrotic syndrome,
dysproteinemias, obstructive liver disease, other drug therapy, alcoholism),
should be excluded, and a lipid profile performed to assess Total cholesterol,
HDL-C, and triglycerides (TG). For individuals with TG less than 400 mg/dL
(less than 4.5 mmol/L), LDL-C can be estimated using the following equation:
LDL-C = Total
cholesterol
[(TG/5) + HDL-C]
For TG levels >400
mg/dL, this equation is less accurate and LDL-C concentrations should be
determined by ultracentrifugation. In hypertriglyceridemic patients, LDL-C may
be low or normal despite elevated Total-C. In such cases Cholestyramine may not
be indicated.
Serum cholesterol and
triglyceride levels should be determined periodically based on NCEP guidelines
to confirm initial and adequate long-term response. A favorable trend in
cholesterol reduction should occur during the first month of Cholestyramine
therapy. The therapy should be continued to sustain cholesterol reduction. If
adequate cholesterol reduction is not attained, increasing the dosage of
Cholestyramine or adding other lipid-lowering agents in combination with
Cholestyramine should be considered.
Since the goal of
treatment is to lower LDL-C, the NCEP 4 recommends that
LDL-C levels be used to initiate and assess treatment response. If LDL-C levels
are not available then Total-C alone may be used to monitor long-term therapy. A
lipoprotein analysis (including LDL-C determination) should be carried out once
a year. The NCEP treatment guidelines are summarized below.
LDL-Cholesterol mg/dL (mmol/L)
Definite AtheroscleroticDisease*
Two or More Other RiskFactors**
Initiation Level
Goal
NO
NO
Greater Than or Equal to 190 (Greater Than or Equal To 4.9)
Less Than 160 (Less Than 4.1)
NO
YES
Greater Than or Equal To 160 (Greater Than or Equal To 4.1)
Less Than 130 (Less Than 3.4)
YES
YES or NO
Greater Than or Equal To 130 (Greater Than or Equal To 3.4)
Less Than or Equal To 100 (Less Than or Equal To 2.6)
* Coronary heart disease or peripheral vascular disease (including symptomatic carotid
artery disease).** Other risk factors for coronary heart disease (CHD) include: age (males greater than or equal to 45 years;
females greater than or equal to 55 years or premature menopause without estrogen replacement therapy);
family history of premature CHD; current cigarette smoking; hypertension;
confirmed HDL-C less than 35 mg/dL (less than 0.91 mmol/L); and diabetes mellitus. Subtract
one risk factor if HDL-C is greater than or equal to 60 mg/dL (greater than or equal to 1.6 mmol/L).
Cholestyramine
monotherapy has been demonstrated to retard the rate of progression 2,3 and increase the rate of regression3
of coronary atherosclerosis.
2) Cholestyramine for
oral suspension is indicated for the relief of pruritus associated with partial
biliary obstruction. Cholestyramine for oral suspension has been shown to have a
variable effect on serum cholesterol in these patients. Patients with primary
biliary cirrhosis may exhibit an elevated cholesterol as part of their disease.