What is colestipol?

From the Guidelines

Colestipol is a bile acid sequestrant medication that is primarily used to lower cholesterol levels in the blood by binding to bile acids in the intestines and preventing their reabsorption, thereby causing the body to use cholesterol to make more bile acids and ultimately reducing cholesterol levels.

Key Points About Colestipol

• It is typically prescribed as an adjunct to diet for patients with primary hypercholesterolemia (elevated LDL cholesterol) 1.
• Colestipol comes in two forms: granules that are mixed with liquids before consumption and tablets, with a usual adult dose ranging from 2 to 16 grams daily, often divided into two doses 1.
• Common side effects include constipation, abdominal pain, gas, and nausea, and it can interfere with the absorption of other medications, which should be taken at least one hour before or four hours after colestipol 1.
• Colestipol is particularly useful for patients who cannot tolerate statins or need additional cholesterol-lowering therapy, and since it is not absorbed into the bloodstream, it is considered relatively safe for long-term use and can be appropriate for pregnant women or patients with liver disease who need cholesterol management.

Mechanism of Action and Efficacy

• The mechanism of action of colestipol involves binding to bile acids in the intestine, impeding their reabsorption, and upregulating the hepatic enzyme cholesterol 7-a-hydroxylase, which increases the conversion of cholesterol to bile acids, leading to increased demand for cholesterol in the liver cells and ultimately resulting in decreased serum LDL-C levels 1.
• The efficacy of colestipol in reducing LDL-C levels has been demonstrated in clinical trials, with doses of 5,10, and 15 grams resulting in 16.3%, 22.8%, and 27.2% reductions in LDL-C, respectively 1.

Considerations for Use

• Colestipol may increase triglyceride levels and cause acute pancreatitis, and it is contraindicated in patients with complete biliary obstruction or a history of serious hypersensitivity to the medication 1.
• It is essential to monitor triglyceride levels and discontinue the medication if signs and symptoms of acute pancreatitis occur, and to avoid concomitant use with other medications that may increase the risk of pancreatitis 1.

From the FDA Drug Label

Colestipol hydrochloride for oral suspension, USP contains colestipol hydrochloride USP, which is a lipid lowering agent for oral use. Colestipol hydrochloride is an insoluble, high molecular weight basic anion-exchange copolymer of diethylenetriamine and 1-chloro-2,3-epoxypropane, with approximately 1 out of 5 amine nitrogens protonated (chloride form). Colestipol is a lipid-lowering agent used to reduce elevated serum total and low-density lipoprotein (LDL) cholesterol in patients with primary hypercholesterolemia.

• It is an insoluble, high molecular weight basic anion-exchange copolymer.
• The mechanism of action involves binding bile acids in the intestine, forming a complex that is excreted in the feces, resulting in a partial removal of bile acids from the enterohepatic circulation 2.

From the Research

Definition and Properties of Colestipol

• Colestipol is an anion exchange resin with bile acid sequestering properties, similar to cholestyramine 3.
• It is used to lower plasma cholesterol concentrations, primarily low-density lipoprotein (LDL) cholesterol, in patients with hypercholesterolaemia 3, 4.

Therapeutic Efficacy

• Colestipol has been shown to reduce total plasma cholesterol concentrations by about 15 to 30% in daily doses of 15 to 30g 3.
• It is effective in patients with primary hypercholesterolaemia without associated hypertriglyceridaemia (type IIa hyperlipoproteinaemia) 3, 5.
• Colestipol can also be used in combination with other lipid-lowering drugs to maximize cholesterol-lowering effects 4, 5.

Side Effects and Tolerability

• Side effects of colestipol treatment are primarily gastrointestinal in nature, as the drug is essentially unabsorbed 3.
• Common side effects include constipation, nausea, and metheorism, which are often transitory and mild 6.
• Colestipol may bind with other concomitantly administered drugs, reducing their absorption or enterohepatic recirculation, and dosage intervals of other concurrent medications should be adjusted to minimize this interaction 3.

Clinical Studies

• Clinical studies have demonstrated the efficacy and safety of colestipol in lowering LDL cholesterol levels and slowing the progression of atherosclerosis 7, 4, 6.
• A study published in 1994 found that colestipol significantly reduced LDL and total cholesterol levels compared to placebo, with varying dosage intervals 7.
• Another study published in 1989 reviewed clinical studies of bile acid sequestrants, including colestipol, and found them to be excellent agents for lowering circulating LDL cholesterol levels 4.