Related Experiment Videos
Fatal drug interaction between cholestyramine and phenprocoumon
Nicola Balmelli1, Frédéric Dominé, Matthias Pfisterer
1Division of Medical Intensive Care, University Hospital, Petersgraben 4, CH-4031, Basel, Switzerland
European Journal of Internal Medicine
|May 22, 2002
Summary
A fatal drug interaction occurred between phenprocoumon and cholestyramine in a patient with a prosthetic aortic valve. Even when administered correctly, cholestyramine can cause dangerous interactions with oral anticoagulants due to enterohepatic cycling.
Area of Science:
- Pharmacology
- Cardiology
- Internal Medicine
Background:
- Drug interactions pose significant risks in patients with prosthetic heart valves.
- Oral anticoagulants like phenprocoumon require careful management to prevent thrombosis and bleeding.
- Cholestyramine is a bile acid sequestrant used to lower cholesterol levels.
Purpose of the Study:
- To report a fatal case of prosthetic aortic valve thrombosis.
- To investigate the drug interaction between phenprocoumon and cholestyramine.
- To highlight the risks of cholestyramine in patients on oral anticoagulants.
Main Methods:
- Case report of a patient with a prosthetic aortic valve.
- Analysis of drug interaction between phenprocoumon and cholestyramine.
- Consideration of enterohepatic cycling and drug half-life.
Main Results:
- The patient developed fatal valve thrombosis.
- The interaction occurred despite correct administration of cholestyramine (>1 hour before phenprocoumon).
- Enterohepatic cycling and phenprocoumon's long half-life contributed to the interaction.
Conclusions:
- Cholestyramine should not be administered to patients treated with drugs undergoing enterohepatic cycling.
- Oral anticoagulants are particularly susceptible to this interaction.
- This case underscores the critical need for awareness of drug interactions in anticoagulated patients.