| Drug treatments: Bile acid resins |

Bile-acid resins and similar agents include:
Bile-acid binding resins work, as their name suggests, by binding to bile in the digestive tract. This reduces cholesterol in the following way:
When used with dietary control, bile acid resins can reduce LDL levels by 15 - 20%. When bile acid resins are combined with nicotinic acid, LDL levels can drop as much as 40 - 60%.

Side effects
Often, people experience constipation, heartburn, gas, and other gastrointestinal problems while taking a drug in this class. These symptoms can become so bothersome that the person wants to change medications.
Colesevelam, the newer resin, appears to produce fewer of the gastrointestinal side effects described.
Over time, deficiencies of vitamins A, D, E, K, and B9 (folic acid) may occur, and vitamin supplements may be necessary. If long-term use of bile acid resins leads to depletion of vitamin K in the body, bleeding problems may occur.
Rarely, toxic effects on the liver have been reported. Patients with liver disorders should be monitored.
Drug interactions
Bile-acid binding resins may interfere with other medications, including:
In order to prevent drug interactions, take medications 1 hour before or 4 - 6 hours after taking the bile acid-binding resins.