From the Guidelines
Cholestyramine is a bile acid sequestrant medication primarily used to lower cholesterol levels, particularly LDL-C, by binding to bile acids in the intestines and preventing their reabsorption, as supported by the most recent evidence from 1.
Mechanism of Action and Indications
The medication works by creating an insoluble complex with bile acids in the intestine, which reduces the amount of cholesterol available for absorption and forces the liver to use more cholesterol to produce new bile acids, thereby lowering blood cholesterol levels. According to 1, Cholestyramine is indicated for the treatment of primary hyperlipidemia as an adjunct to diet.
Dosage and Administration
The typical dose of Cholestyramine ranges from 8-16 grams per day, divided into 2 doses, as stated in 1. It is essential to mix the powder with liquid, such as water or a non-carbonated beverage, and take it with meals to minimize gastrointestinal side effects.
Side Effects and Interactions
Common side effects of Cholestyramine include constipation, bloating, gas, and nausea, as reported in 1. The medication can also interfere with the absorption of other medications and fat-soluble vitamins, so it is recommended to take Cholestyramine at least 1 hour before or 4-6 hours after other medications.
Clinical Considerations
When prescribing Cholestyramine, it is crucial to consider the potential for increased triglyceride levels and the risk of acute pancreatitis, as noted in 1. Additionally, the medication may cause gastrointestinal obstruction, and patients with a history of bowel obstruction or gastroparesis should be monitored closely.
Evidence-Based Recommendation
Based on the most recent and highest-quality evidence from 1, Cholestyramine is a recommended treatment option for patients with primary hyperlipidemia who require LDL-C lowering, particularly when used as an adjunct to diet and exercise. However, it is essential to carefully evaluate the potential benefits and risks of Cholestyramine in individual patients, considering their unique clinical characteristics and medical history.
From the FDA Drug Label
Cholesterol is probably the sole precursor of bile acids. During normal digestion, bile acids are secreted into the intestines. A major portion of the bile acids is absorbed from the intestinal tract and returned to the liver via the enterohepatic circulation. Only very small amounts of bile acids are found in normal serum Cholestyramine resin adsorbs and combines with the bile acids in the intestine to form an insoluble complex which is excreted in the feces. The increased fecal loss of bile acids due to cholestyramine resin administration leads to an increased oxidation of cholesterol to bile acids, a decrease in beta lipoprotein or low density lipoprotein plasma levels and a decrease in serum cholesterol levels.
The use of Cholestyramine (Questran), a bile acid sequestrant, is to:
- Decrease serum cholesterol levels by increasing the oxidation of cholesterol to bile acids
- Reduce low-density lipoprotein (LDL) plasma levels
- Treat hypercholesterolemia by removing bile acids from the enterohepatic circulation
- Relieve pruritus in patients with partial biliary obstruction by reducing excess bile acids deposited in the dermal tissue 2
From the Research
Use of Cholestyramine
Cholestyramine, a bile acid sequestrant, is used to treat hypercholesterolemia. The key uses of Cholestyramine include:
- Lowering total cholesterol and low-density lipoprotein (LDL) cholesterol levels in patients with severe hypercholesterolemia 3, 4, 5, 6, 7
- Reducing the risk of cardiovascular disease by decreasing the levels of LDL cholesterol and increasing the levels of high-density lipoprotein (HDL) cholesterol 3, 4, 5, 6, 7
Mechanism of Action
Cholestyramine works by binding to bile acids in the intestine and preventing their reabsorption into the bloodstream. This leads to an increase in the excretion of bile acids, which in turn reduces the amount of cholesterol produced in the liver 3, 4, 5, 6, 7
Efficacy and Tolerability
Studies have shown that Cholestyramine is effective in reducing total cholesterol and LDL cholesterol levels, with significant reductions observed in patients with severe hypercholesterolemia 3, 4, 5, 6, 7. However, Cholestyramine may cause gastrointestinal side effects, such as constipation, and may increase triglyceride levels in some patients 4, 6, 7
Specific Patient Populations
Cholestyramine has been studied in various patient populations, including:
- Patients with primary type-IIa hyperlipoproteinemia, where it was shown to be effective in lowering cholesterol and LDL cholesterol levels 5
- Patients with non-insulin-dependent diabetes mellitus (NIDDM), where it was shown to reduce LDL cholesterol levels and improve glycemic control 7
- Patients with severe primary hypercholesterolemia, where it was compared to lovastatin and shown to be less effective but still a viable treatment option 6