Fedratinib with Telithromycin Interaction Details
Brand Names Associated with Telithromycin
- Ketek®
- Telithromycin
Medical Content Editor Dr. Brian Staiger, PharmD
Last updated
Dec 27, 2023
Interaction Effect
Increased fedratinib and/or CYP3A4 substrate exposure and an increased frequency or severity of adverse reactions
Interaction Summary
Fedratinib is metabolized by CYP3A4 and also inhibits the enzyme. Coadministration with a strong CYP3A4 inhibitor increases fedratinib exposure, and may increase the risk for adverse effects. Coadministration of fedratinib with a CYP3A4 substrate also increases substrate exposure and risk of adverse effects of that drug. Coadministration of ketoconazole 200 mg twice daily (strong CYP3A inhibitor) with single-dose fedratinib 300 mg increased fedratinib AUC by 3-fold in a clinical study, and coadministration of a single dose of midazolam 2 mg (CYP3A4 substrate) with fedratinib increased midazolam AUC by 4-fold in another study. Consider alternative therapies that do not strongly inhibit CYP3A4 activity when the patient is receiving fedratinib. If coadministration of fedratinib with a CYP3A4 substrate that also strongly inhibits CYP3A4 is required, reduce fedratinib to 200 mg orally once daily and monitor for adverse reactions and adjust the dose of the other drug. After discontinuation of a strong CYP3A4 inhibitor, increase fedratinib to 300 mg once daily for 2 weeks and then to 400 mg once daily thereafter, as tolerated.
Severity
Major
Onset
Unspecified
Evidence
Probable
How To Manage Interaction
Fedratinib is a CYP3A4 substrate that also inhibits the enzyme. Consider alternative therapies that do not strongly inhibit CYP3A4 activity during fedratinib therapy. If coadministration of fedratinib with a drug that is a CYP3A4 substrate and a strong CYP3A4 inhibitor is required, reduce fedratinib to 200 mg orally once daily and monitor for adverse reactions and adjust the dose of the other drug. After discontinuation of a strong CYP3A4 inhibitor, increase fedratinib to 300 mg once daily for 2 weeks and then to 400 mg once daily thereafter, as tolerated.
Mechanism Of Interaction
Inhibition of CYP3A4-mediated metabolism of fedratinib; inhibition of CYP3A4-mediated substrate metabolism by fedratinib
Literature Reports
A) Coadministration of ketoconazole 200 mg twice daily (a strong CYP3A inhibitor) with a single fedratinib dose of 300 mg increased fedratinib AUC(0 to infinity) by 3-fold in a clinical study. Pharmacokinetic modeling predicts coadministration of fedratinib 400 mg once daily with a strong CYP3A4 inhibitor (ketoconazole 400 mg once daily) to increase steady-state fedratinib AUC by 2-fold, or with a moderate CYP3A4 inhibitor (eg, erythromycin 500 mg three times daily.
B) Coadministration of a single dose of midazolam 2 mg (CYP3A substrate) with fedratinib increased midazolam AUC by 4-fold .
Telithromycin Overview
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Telithromycin is used to treat certain types of pneumonia (an infection of the lungs) that is caused by bacteria. Telithromycin is in a class of medications called ketolide antibiotics. It works by killing bacteria.
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Antibiotics such as telithromycin not work for colds, flu, or other viral infections. Taking antibiotics when they are not needed increases your risk of getting an infection later that resists antibiotic treatment.
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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.