NCLEX Review Guide: Bile Acid Sequestrants

Mechanism of Action

• Bile acid sequestrants bind to bile acids in the intestine, preventing their reabsorption and forcing the liver to use cholesterol to synthesize new bile acids. This mechanism effectively lowers serum cholesterol levels by depleting the body's cholesterol stores.
• Common medications include cholestyramine (Questran), colesevelam (Welchol), and colestipol (Colestid), all working through the same binding mechanism in the GI tract.

Therapeutic Uses

• Primary indication is hypercholesterolemia management, particularly when statins are contraindicated or insufficient. These agents specifically target LDL cholesterol reduction while having minimal systemic absorption.
• Secondary use includes pruritus management in cholestatic liver disease by reducing bile acid accumulation that causes intense itching.

1. Mix powder thoroughly with 4-6 oz of liquid to prevent esophageal obstruction
2. Take with meals to maximize bile acid binding when bile is released
3. Maintain adequate fluid intake to prevent constipation
4. Schedule other medications appropriately to avoid drug interactions

Common Side Effects

• Gastrointestinal effects dominate the side effect profile, including constipation (most common), bloating, flatulence, and nausea due to the medication's action in the intestinal tract.
• Fat-soluble vitamin deficiencies can develop with long-term use as these medications can bind vitamins A, D, E, and K, preventing their absorption.

Significant Interactions

• Complete biliary obstruction is an absolute contraindication as bile acids cannot reach the intestine for the medication to work effectively.
• Use caution in patients with gastroparesis or severe GI motility disorders as these conditions can be exacerbated by the medication's GI effects.