Cholestyramine with Phenprocoumon Interaction Details

Brand Names Associated with Cholestyramine

  • Cholestyramine Resin
  • Locholest®
  • Locholest® Light
  • Prevalite®
  • Questran®
  • Questran® Light

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Last updated Feb 28, 2024

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Interaction Effect

Decreased effects of phenprocoumon

Interaction Summary

Cholestyramine can bind oral anticoagulants in the gut and limit their absorption, thus impairing their activity. Separating the doses of the drugs by several hours may lessen the impact of this interaction but since phenprocoumon undergoes enterohepatic recirculation, time separation of the doses will not eliminate the problem[1][2].

Severity

Moderate

Onset

Delayed

Evidence

Probable

How To Manage Interaction

Monitor the International Normalized Ratio (INR) whenever cholestyramine is added to or discontinued during co-treatment with phenprocoumon, or whenever cholestyramine dose is changed during concomitant therapy. Dose timing adjustments may not adequately prevent the interaction.

Mechanism Of Interaction

Decreased phenprocoumon absorption

Literature Reports

A) Cholestyramine 4 g TID given orally doubles the total clearance of phenprocoumon. When phenprocoumon is given intravenously, the elimination is increased by cholestyramine due to an interruption in the enterohepatic circulation of the drug [3]. This phenomenon was used therapeutically in a case of suicidal overdose with phenprocoumon. The half-life of phenprocoumon was reduced from 6.8 days to 3.5 days during the administration of cholestyramine 4 g three times daily for 10 days [2].

References

    1 ) Jahnchen E, Meinertz T, Gilfrich HJ, et al: Enhanced elimination of warfarin during treatment with cholestyramine. Br J Clin Pharmacol 1978; 5:437-440.

    2 ) Meinertz T, Gilfrich MJ, Groth U, et al: Interruption of the enterohepatic circulation of phenprocoumon by cholestyramine. Clin Pharmacol Ther 1977a; 21:731-735.

    3 ) Meinertz T, Gilfrich MJ, Bork R, et al: Treatment of phenprocoumon intoxication with cholestyramine. Br Med J 1977; 2:439.

Cholestyramine Overview

  • Cholestyramine is used with diet changes (restriction of cholesterol and fat intake) to reduce the amount of cholesterol and certain fatty substances in your blood. Accumulation of cholesterol and fats along the walls of your arteries (a process known as atherosclerosis) decreases blood flow and, therefore, the oxygen supply to your heart, brain, and other parts of your body. Lowering your blood level of cholesterol and fats may help to prevent heart disease, angina (chest pain), strokes, and heart attacks.

  • This medication is sometimes prescribed for other uses; ask your doctor or pharmacist for more information.

See More information Regarding Cholestyramine Resin

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Definitions

Severity Categories

Contraindicated

These drugs, generally, should not be used together simultaneously due to the high risk of severe adverse effects. Combining these medications can lead to dangerous health outcomes and should be strictly avoided unless otherwise instructed by your provider.


Major

This interaction could result in very serious and potentially life-threatening consequences. If you are taking this drug combination, it is very important to be under close medical supervision to minimize severe side effects and ensure your safety. It may be necessary to change a medication or dosage to prevent harm.


Moderate

This interaction has the potential to worsen your medical condition or alter the effectiveness of your treatment. It's important that you are monitored closely and you potentially may need to make adjustments in your treatment plan or drug dosage to maintain optimal health.


Minor

While this interaction is unlikely to cause significant problems, it could intensify side effects or reduce the effectiveness of one or both medications. Monitoring for changes in symptoms and your condition is recommended, and adjustments may be made if needed to manage any increased or more pronounced side effects.

Onset

Rapid: Onset of drug interaction typically occurs within 24 hours of co-administration.

Delayed: Onset of drug interaction typically occurs more than 24 hours after co-administration.

Evidence

Level of documentation of the interaction.

Established: The interaction is documented and substantiated in peer-reviewed medical literature.

Theoretical: This interaction is not fully supported by current medical evidence or well-documented sources, but it is based on known drug mechanisms, drug effects, and other relevant information.

How To Manage The Interaction

Provides a detailed discussion on how patients and clinicians can approach the identified drug interaction as well as offers guidance on what to expect and strategies to potentially mitigate the effects of the interaction. This may include recommendations on adjusting medication dosages, altering the timing of drug administration, or closely monitoring for specific symptoms.

It's important to note that all medical situations are unique, and management approaches should be tailored to individual circumstances. Patients should always consult their healthcare provider for personalized advice and guidance on managing drug interactions effectively.

Mechanism Of Interaction

The theorized or clinically determined reason (i.e., mechanism) why the drug-drug interaction occurs.

Disclaimer: The information provided on this page is for informational purposes only and should not be considered medical advice. Always consult with a qualified healthcare professional regarding your specific circumstances and medical conditions.

Where Does Our Information Come From?

Information for our drug interactions is compiled from several drug compendia, including:

The prescribing information for each drug, as published on DailyMED, is also used. 

Individual drug-drug interaction detail pages contain references specific to that interaction. You can click on the reference number within brackets '[]' to see what reference was utilized.

The information posted is fact-checked by HelloPharmacist clinicians and reviewed quarterly.