Brand names: Prevalite, Questran, Questran Light
Drug class: Bile Acid Sequestrants
VA class: CV350
CAS number: 11041-12-6

Medically reviewed by Drugs.com on Jul 17, 2023. Written by ASHP.

Introduction

Antilipemic agent; bile acid sequestrant.

Uses for Cholestyramine

Dyslipidemias

Adjunct to dietary therapy to decrease elevated serum total and LDL-cholesterol concentrations in the management of primary hypercholesterolemia in patients who do not respond adequately to diet.

As effective as colestipol in lowering serum cholesterol concentrations. Select bile acid sequestrant based on patient tolerance, including palatability and taste preference, and cost.

AHA/ACC cholesterol management guideline states that lifestyle modification is the foundation of cardiovascular risk reduction. If pharmacologic therapy is needed, statins are first-line drugs of choice because of their demonstrated benefits in reducing risk of ASCVD. The addition of a nonstatin drug (e.g., ezetimibe, bile acid sequestrants, PCSK9 inhibitor) may be considered in certain circumstances such as in patients with very severe elevations of LDL-cholesterol concentrations who are not achieving adequate LDL lowering with maximally tolerated statin therapy.

Pruritus Associated with Partial Cholestasis

Relief of pruritus associated with partial cholestasis. Effects on serum cholesterol in these patients is variable.

Cholestyramine Dosage and Administration

General

• Patients should be placed on a standard lipid-lowering diet before initiation of cholestyramine therapy and should remain on this diet during treatment with the drug.

Monitoring during Antilipemic Therapy

• Determine serum cholesterol and triglyceride concentrations prior to and regularly (e.g., every 3–6 months) during cholestyramine therapy.

Administration

Oral Administration

Administer orally at mealtime.

Do not administer the powder in its dry form; always mix with water or other fluids before ingesting.

Mix cholestyramine powder for oral suspension with an adequate amount (60–180 mL for 1 packet or level scoop of powder) of a liquid (e.g., water, fruit juice, other noncarbonated beverage) and stir to uniform consistency.

Palatability and compliance may be increased if the entire next-day’s dose is mixed in one of these liquids in the evening and then refrigerated.

Use of a heavy or pulpy fruit juice may minimize complaints about consistency of suspensions of the drug.

If a carbonated beverage is used, mix the powder slowly in a large glass to minimize excessive foaming. To minimize excessive swallowing of air, advise patients to avoid rapid ingestion of suspensions of the drug.

Alternatively, mix cholestyramine powder with a highly fluid soup or a pulpy fruit with a high moisture content such as applesauce or crushed pineapple.

Instruct patients to take other drugs at least 1 hour before or 4–6 hours after taking cholestyramine to minimize possible interference with absorption. (See Effects on GI Absorption of Drugs under Interactions.)

Dosage

Available as cholestyramine resin; dosage expressed in terms of anhydrous (i.e., dried) cholestyramine resin.

Each 9 g of Questran or generic cholestyramine (1 dose, 1 packet, or 1 level scoop), 5.5 g of Prevalite (1 dose, 1 packet, or 1 level scoop), or 5 g of Questran Light or generic cholestyramine light (1 dose, 1 packet, or 1 level scoop) contains about 4 g of anhydrous cholestyramine resin.

In calculating pediatric dosages, each 100 mg of the commercially available powders contains either 44.4 mg (e.g., Questran, generic cholestyramine), 72.7 mg (e.g., Prevalite), or 80 mg (e.g., Questran Light, generic cholestyramine light) of anhydrous cholestyramine resin.

Pediatric Patients

Dyslipidemias† [off-label]

Oral

240 mg/kg daily in 2–3 divided doses suggested by manufacturers and some clinicians.

Adults

Dyslipidemias or Pruritus Associated with Partial Cholestasis

Oral

Initially, 4 g of anhydrous resin (1 packet or 1 level scoop) once or twice daily at mealtime.

Increase dosage gradually to minimize adverse GI effects (e.g., fecal impaction).

Usual maintenance dosage recommended by manufacturers is 8–16 g daily, given in 2 divided doses. Usual dosage range suggested by Third Report of the National Cholesterol Education Program (NCEP) (Adult Treatment Panel [ATP] III) is 4–16 g daily.

Although the recommended dosing schedule is twice daily, may be administered in 1–6 doses per day.

In patients with preexisting constipation: Initially, 4 g of anhydrous resin (1 packet or 1 level scoop) once daily for 5–7 days; then increase dosage to 4 g twice daily and monitor constipation and serum lipoprotein values, at least twice, 4–6 weeks apart. Thereafter, increase dosage as needed by 1 dose (i.e., 4 g) per day (at monthly intervals) with periodic monitoring of serum lipoprotein values.

If constipation worsens or the desired effect is not achieved with acceptable adverse effects with the usual dosage of 1–6 doses (i.e., 4–24 g) per day, consider combined therapy or alternative treatment.

Prescribing Limits

Pediatric Patients

Oral

Maximum 8 g daily.

Adults

Oral

Maximum 24 g (6 packets or 6 level scoops) daily.

Related/similar drugs

atorvastatin, rosuvastatin, simvastatin, ezetimibe, Lipitor, fenofibrate, Crestor

Cautions for Cholestyramine

Contraindications

• Complete biliary obstruction in which no bile products reach the intestine.

• Known hypersensitivity to cholestyramine or any ingredient in the formulation.

Warnings/Precautions

Warnings

Phenylketonuria

Individuals with phenylketonuria (i.e., homozygous genetic deficiency of phenylalanine hydroxylase) and other individuals who must restrict their intake of phenylalanine should be warned that each 5-g dose of Questran Light, 5-g dose of generic cholestyramine light, or 5.5-g dose of Prevalite contains aspartame (NutraSweet), which is metabolized in the GI tract to provide about 14, 14, or 14.1 mg, respectively, of phenylalanine following oral administration.

Major Toxicities

GI Effects

Mild constipation has occurred, especially after high doses and in patients >60 years of age. Exacerbation of preexisting constipation and aggravation of hemorrhoids secondary to constipation may occur.

Encourage increased fluid and fiber intake to alleviate constipation; a stool softener can be added if necessary. In addition, adjust dosage carefully and titrate slowly to minimize adverse GI effects (e.g., fecal impaction). (See Dosage under Dosage and Administration.)

Make particular effort to avoid constipation in patients with symptomatic CHD.

Discontinuance of cholestyramine therapy may be required in some patients.

Abdominal discomfort and/or pain, flatulence, nausea, vomiting, diarrhea, eructation, anorexia, biliary colic, and steatorrhea also reported. Intestinal obstruction, which rarely has been fatal, reported in pediatric patients.

General Precautions

Hypertriglyceridemia

Use with caution in patients with baseline triglyceride concentrations of 250-299 mg/dL; discontinue when triglyceride concentrations <400 mg/dL.

Do not use in patients with baseline fasting triglyceride concentrations ≤300 mg/dL or in those with primary dysbetalipoproteinemia (Frederickson type III).

Fat-soluble Vitamin Deficiency

May interfere with the absorption of fat-soluble vitamins (e.g., vitamins A, D, E, K). Bleeding tendency due to hypoprothrombinemia secondary to vitamin K deficiency, night blindness secondary to vitamin A deficiency, and vitamin D deficiency have been reported. (See Specific Drugs under Interactions.)

Hyperchloremic Acidosis

Because cholestyramine is the chloride form of an anion-exchange resin, there is a possibility that prolonged use may lead to the development of hyperchloremic acidosis. Hyperchloremic acidosis reported in children.

Caution during long-term therapy in patients with renal impairment or volume depletion and in patients receiving concomitant spironolactone.

Specific Populations

Pregnancy

Category C.

Interferes with absorption of fat-soluble vitamins, and regular prenatal supplementation may not be adequate. (See Specific Drugs under Interactions.)

Lactation

Use with caution; possible lack of proper vitamin absorption associated with cholestyramine therapy may have an effect on nursing infants.

Pediatric Use

Safety and efficacy of long-term administration not established. The potential effect of cholestyramine on vitamin absorption and on electrolytes should be considered.

Common Adverse Effects

Constipation, osteoporosis, rash, irritation of the skin/tongue/perianal area.

Drug Interactions

Effects on GI Absorption of Drugs

May bind to a number of drugs (e.g., phenylbutazone, warfarin, propranolol, tetracycline, penicillin G, phenobarbital, thyroid and thyroxine preparations, estrogens and progestins, digoxin, iron salts, loperamide) in the GI tract and may delay or reduce their absorption. Instruct patients to administer other drugs at least 1 hour before or 4–6 hours after cholestyramine (or allow as long a time interval as possible between ingestion of other drugs and cholestyramine).

May interfere with the pharmacokinetics of drugs that undergo enterohepatic circulation.

Consider the possibility that discontinuance of cholestyramine in patients stabilized on potentially toxic drugs that bind to the resin may lead to toxicity and that administration of cholestyramine to patients stabilized on other drugs may reduce the effect of these drugs.

Specific Drugs

Cholestyramine Pharmacokinetics

Absorption

Bioavailability

Not absorbed from the GI tract.

Onset

Antilipemic response usually occurs within 1 month. In patients with pruritus associated with partial cholestasis, relief of pruritus usually occurs within 1–3 weeks after initiation of therapy.

Elimination

Elimination Route

Binds to bile acids in the intestine and forms a nonabsorbable complex that is excreted in feces.

Stability

Storage

Oral

Powder for Oral Suspension

20–25°C (may be exposed to 15–30°C).

Actions and Spectrum

• Binds to bile acids in the intestine and forms a nonabsorbable complex that is excreted in feces. Partial removal of bile acids from the enterohepatic circulation results in increased conversion of cholesterol to bile acids in the liver. This causes an increased demand for cholesterol in liver cells, resulting in a compensatory increase in hepatic uptake (and thus systemic clearance) of circulating LDL-cholesterol.

• Reduces serum total and LDL-cholesterol concentrations.

• In patients with partial biliary obstruction, reduction of serum bile acid concentrations reduces excess bile acids deposited in dermal tissues, resulting in relief of pruritus.

Advice to Patients

• Importance of advising patients that sipping or holding cholestyramine suspension in the mouth for prolonged periods may lead to changes in the surface of the teeth, resulting in discoloration, erosion of enamel, or decay. Maintain good oral hygiene.

• Importance of adhering to nondrug therapies and measures, including dietary management, weight control, physical activity, and management of potentially contributory disease (e.g., diabetes mellitus).

• For phenylketonurics, importance of informing them that Questran Light, generic cholestyramine light, and Prevalite contain aspartame.

• Importance of women informing clinicians if they are or plan to become pregnant or plan to breast-feed.

• Importance of informing clinicians of existing or contemplated concomitant therapy, including prescription and OTC drugs.

• Importance of informing patients of other important precautionary information. (See Cautions.)

Preparations

Excipients in commercially available drug preparations may have clinically important effects in some individuals; consult specific product labeling for details.

Please refer to the ASHP Drug Shortages Resource Center for information on shortages of one or more of these preparations.

* available from one or more manufacturer, distributor, and/or repackager by generic (nonproprietary) name

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