What is the labeled use for Cholestyramine (bile acid sequestrant)?

Labeled Uses for Cholestyramine

Cholestyramine is primarily indicated as adjunctive therapy to diet for the reduction of elevated serum cholesterol in patients with primary hypercholesterolemia (elevated LDL cholesterol) who do not respond adequately to diet. 1

Primary FDA-Approved Indication

Cholestyramine is a bile acid sequestrant with the following labeled use:

• Treatment of primary hypercholesterolemia (elevated LDL cholesterol) in patients who do not respond adequately to dietary modifications 1
• May be useful to lower LDL cholesterol in patients who also have hypertriglyceridemia, but not indicated where hypertriglyceridemia is the abnormality of most concern 1

Mechanism of Action

Cholestyramine works by:

• Binding bile acids in the intestinal lumen, forming an insoluble complex 2
• Preventing enterohepatic reuptake of bile acids in the terminal ileum 2
• Depleting the liver of bile acids, which signals increased bile acid production from cholesterol 2
• Depleting intracellular cholesterol pools, which upregulates LDL receptor activity 2
• Reducing LDL cholesterol levels by 18-25% at standard doses 2

Dosing Information

• Starting dose: 2-4 g/day 3
• Gradual titration based on response to minimize side effects 2
• Maximum dose: 24 g/day 3
• Administered as powder to be mixed with liquids or soft foods 1

Clinical Efficacy

Cholestyramine has demonstrated effectiveness in:

• Reducing total cholesterol by approximately 28% 4
• Reducing LDL cholesterol by approximately 33% 4
• Reducing Apo B lipoprotein by approximately 18% 4
• Providing approximately 20% cardiovascular disease risk reduction in primary prevention 3

Important Monitoring and Precautions

• Serum cholesterol and triglyceride levels should be determined periodically to confirm initial and adequate long-term response 1
• A favorable trend in cholesterol reduction should occur during the first month of therapy 1
• Monitor for potential increases in triglyceride levels 3
• Long-term use may affect fat-soluble vitamin absorption, particularly folate, vitamins A and E 5
• Consider supplementation with folic acid for patients on long-term therapy 5

Contraindications

Cholestyramine is contraindicated in:

• Patients with triglycerides >500 mg/dL 3
• History of hypertriglyceridemia-induced pancreatitis 3
• Complete biliary obstruction 6
• Patients with extensive ileal resection (>100 cm) or severe ileal involvement 2

Common Side Effects

• Gastrointestinal effects: constipation (most common), nausea, bloating, abdominal discomfort 3
• Reduced absorption of other medications if taken simultaneously 3
• Potential for steatorrhea with high doses 5

Drug Interactions

• Other medications should be taken at least 1 hour before or 4-6 hours after cholestyramine to avoid impeding their absorption 3
• May interfere with absorption of fat-soluble vitamins (A, D, E, K) 5

Alternative Bile Acid Sequestrants

When cholestyramine is not tolerated, alternatives include:

• Colestipol: Similar efficacy with potentially better tolerability 3
• Colesevelam: Better tolerability profile with adverse event rates similar to placebo, available in tablet form 3

Cholestyramine remains an effective option for LDL cholesterol reduction in patients who cannot tolerate or have inadequate response to other lipid-lowering therapies, with established evidence for cardiovascular risk reduction.