Drug General Information (ID: DDI5MRUTGP)
Drug Name			Cholestyramine		Drug Info		Chenodeoxycholic acid		Drug Info
Drug Type		Small molecule				Small molecule
Therapeutic Class		Bile Acid Sequestrants				Gallstone Solubilizing Agents
Structure

Mechanism of Cholestyramine-Chenodeoxycholic acid Interaction (Severity Level: Moderate)
Complex formation Click to Show/Hide Mechanism Graph
Drug Name		Cholestyramine				Chenodeoxycholic acid
Mechanism		Anion exchange resin/polymer				Binds to anion exchange resin/polymer
Key Mechanism Factor 1
		Factor Name		Chelation
		Factor Description		Chelation is a direct drug interaction that usually involves the formation of dimers or trimers, resulting in larger complexes and poorer absorption.
Mechanism Description		Decreased absorption of Cholestyramine due to formation of complexes caused by Chenodeoxycholic acid

Recommended Action
Management		As with other drugs whose absorption may be reduced by bile acid sequestering agents, chenodeoxycholic acid should be administered at least 4 hours before the bile acid sequestering agent. However, adjusting the dosing interval may not completely prevent the interaction.

References
1	Product Information. Chenodal (chenodeoxycholic acid). Manchester Pharmaceutical, Fort Collins, CO.
2	Product Information. Questran (cholestyramine). Par Pharmaceutical Inc, Chestnut Ridge, NY.
3	Product Information. Welchol (colesevelam) Daiichi Sankyo, Inc., Parsippany, NJ.