Quantalan is a brand name for the generic drug cholestyramine, a medication that belongs to a class of drugs known as bile acid sequestrants. It is not absorbed systemically into the bloodstream but instead performs its therapeutic action within the gastrointestinal tract. By binding to bile acids, it creates an insoluble complex that is then excreted from the body. This action forces the liver to convert more cholesterol into bile acids to compensate for the loss, which in turn reduces low-density lipoprotein (LDL), or "bad," cholesterol levels in the blood.
The Mechanism of Action
Cholesterol is the primary precursor for bile acids, which are produced in the liver and stored in the gallbladder. They are released into the intestine to help with the digestion and absorption of fats. Under normal circumstances, most bile acids are reabsorbed from the small intestine and recycled back to the liver in what is known as enterohepatic circulation.
When a patient takes Quantalan, the cholestyramine resin, a large, non-absorbable polymer, binds to these bile acids in the intestine. This binding prevents their reabsorption. Because the body loses more bile acids through fecal excretion, the liver's pool of bile acids is depleted. To restore its bile acid supply, the liver begins converting more of the available cholesterol into bile acids. This increased demand for cholesterol up-regulates LDL receptors on the liver's surface, which pull LDL and intermediate-density lipoprotein (IDL) from the bloodstream, thereby lowering serum cholesterol levels.
Indications for Use
Quantalan is used to treat several conditions related to cholesterol metabolism and bile acid balance. It is often used as an adjunctive therapy alongside diet and exercise when lifestyle changes alone are insufficient.
- Primary Hypercholesterolemia: A key indication is the reduction of elevated serum cholesterol, particularly LDL, in patients with primary hypercholesterolemia.
- Pruritus from Biliary Obstruction: It is effective in relieving itching (pruritus) associated with partial biliary obstruction by reducing the levels of pruritogenic factors circulating in the blood.
- Bile Acid Diarrhea: In an off-label use, cholestyramine is prescribed to treat chronic diarrhea caused by bile acid malabsorption, which can occur after certain bowel surgeries like ileal resection.
- Thyrotoxicosis: It can be used as an adjunct in treating thyrotoxicosis by enhancing the clearance of thyroid hormones from the enterohepatic circulation.
Administration
Quantalan is available as a powder that must always be mixed with a liquid before ingestion. It should never be taken in its dry form.
Proper mixing and administration are essential for safety and efficacy:
- Measure the prescribed amount according to healthcare provider instructions.
- Mix the powder thoroughly in an adequate amount of liquid, such as water, milk, or non-carbonated fruit juice, as directed by the instructions.
- You can also mix the powder with applesauce, crushed pineapple, or thin soups to improve palatability.
- Drink the entire mixture slowly. Rinsing the glass with more liquid and drinking it ensures the full dose is consumed.
- To avoid potential drug interactions, take other oral medications at least one hour before or four to six hours after taking Quantalan, as advised by a healthcare professional.
Side Effects and Considerations
The most common side effect of Quantalan is constipation, which is often related to the amount taken and more frequent in older patients. Other potential side effects include:
- Bloating and gas
- Nausea, vomiting, and stomach pain
- Diarrhea or upset stomach
- Loss of appetite
- Vitamin deficiencies (particularly fat-soluble vitamins A, D, E, and K)
- Hyperchloremic metabolic acidosis with prolonged use
- Tooth discoloration or decay due to prolonged contact with the suspension
Patients should increase fluid and fiber intake to help manage constipation. In cases of severe or persistent side effects, a doctor may adjust the amount or suggest a stool softener.
Drug Interactions
As an anion-exchange resin, Quantalan can bind to other drugs in the intestine, reducing or delaying their absorption. This is why timing is critical when taking other medications. Interactions have been noted with:
- Warfarin (a blood thinner)
- Digoxin (a heart medication)
- Thyroid hormones
- Thiazide diuretics
- Certain antibiotics (e.g., tetracycline, penicillin G)
- Fat-soluble vitamins (A, D, E, and K) and folic acid
Patients taking these or other medications should adhere strictly to their doctor's instructions for timing doses.
Quantalan (Cholestyramine) vs. Colestipol
Quantalan (cholestyramine) and colestipol (Colestid) are both bile acid sequestrants used for similar purposes, but they have key differences.
| Feature | Quantalan (Cholestyramine) | Colestipol (Colestid) |
|---|---|---|
| Drug Form | Powder for oral suspension | Tablet and granule forms |
| Additional Use | Effective in relieving pruritus (itching) from partial biliary obstruction | Does not typically relieve pruritus in cholestasis |
| Administration | Must be mixed with liquid; can cause tooth discoloration if not taken properly | Tablets may be large and difficult to swallow for some patients |
| Side Effect Profile | GI upset (constipation, bloating, gas); potential for vitamin malabsorption | Similar GI side effects; also potential for vitamin malabsorption |
Conclusion
Quantalan is a medication that offers effective treatment for high cholesterol and specific conditions like pruritus and bile acid diarrhea. It works locally within the digestive tract, distinguishing it from systemically absorbed drugs like statins. However, its use requires careful attention to administration instructions, potential side effects—especially constipation—and interactions with other medications. Patients should always follow their healthcare provider's directions for optimal therapeutic benefit and to mitigate potential complications. Given its binding properties, it remains an important tool for managing specific lipid and bile-acid-related disorders.
Drugs.com offers a comprehensive drug interaction checker for patients needing to cross-reference their medications, including Quantalan.
