Bile acid sequestrants bind with cholesterol-containing bile acids in the intestines and are then eliminated in the stool. The usual effect of bile acid sequestrants is to lower LDL-cholesterol by about 10 to 20 percent. Small doses of sequestrants can produce useful reductions in LLDL-cholesterol.

Bile acid sequestrants are sometimes prescribed with a statin to increase cholesterol reduction. When these drugs are combined, their effects are added together to lower LDL-cholesterol by over 40 percent. Cholestyramine, colestipol, and colesevelam are the three main bile acid sequestrants currently available.

These three drugs are available as powders or tablets. They are not absorbed from the gastrointestinal tract and 30 years of experience with the sequestrants indicate that their long-term use is safe.

Bile acid sequestrant powders must be mixed with water or fruit juice and taken once or twice (rarely three times) daily with meals. Tablets must be taken with large amounts of fluids to avoid gastrointestinal symptoms. Sequestrant therapy may produce a variety of symptoms including constipation, bloating, nausea, and gas.

The bile acid sequestrants are not prescribed as the sole medicine to lower your cholesterol if you have high triglycerides or a history of severe constipation.

Although sequestrants are not absorbed, they may interfere with the absorption of other medicines if taken at the same time. Other medications therefore should be taken at least 1 hour before or 4 to 6 hours after the sequestrant. Talk to your doctor about the best time to take this medicine, especially if you take other medications.