Fluconazole with Erlotinib Interaction Details
Brand Names Associated with Fluconazole
- Diflucan®
- Fluconazole
Brand Names Associated with Erlotinib
- Erlotinib
- Tarceva®
Medical Content Editor Dr. Brian Staiger, PharmD
Last updated
Dec 18, 2023
Interaction Effect
Increased erlotinib exposure
Interaction Summary
Use caution when administering erlotinib (a CYP3A4 substrate) together with fluconazole (a moderate CYP3A4 inhibitor) as concomitant use may result in elevated erlotinib plasma concentrations. While this interaction has not been specifically studied, concurrent use of erlotinib and ketoconazole (a potent CYP3A4 inhibitor) resulted in an 67% increase in erlotinib AUC.. Fluconazole-mediated enzyme inhibition may persist for 4 to 5 days after discontinuation. If concomitant use is required, carefully monitor for erlotinib-associated adverse effects . Dosage adjustments of erlotinib may be required .
Severity
Moderate
Onset
Unspecified
Evidence
Theoretical
How To Manage Interaction
Caution is advised when using erlotinib (a CYP3A4 substrate) together with fluconazole (a moderate CYP3A4 inhibitor) as concomitant use may result in elevated erlotinib plasma concentrations. Fluconazole-mediated enzyme inhibition may persist for 4 to 5 days after discontinuation. If concomitant use is required, carefully monitor for erlotinib-associated adverse effects . Dosage adjustments of erlotinib may be required .
Mechanism Of Interaction
Inhibition of CYP3A4-mediated erlotinib metabolism by fluconazole
Literature Reports
A) During drug interaction studies, coadministration of erlotinib and ketoconazole (a strong CYP3A4 inhibitor) resulted in a 67% increase in erlotinib AUC .
Fluconazole Overview
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Fluconazole is used to treat fungal infections, including yeast infections of the vagina, mouth, throat, esophagus (tube leading from the mouth to the stomach), abdomen (area between the chest and waist), lungs, blood, and other organs. Fluconazole is also used to treat meningitis (infection of the membranes covering the brain and spine) caused by fungus. Fluconazole is also used to prevent yeast infections in patients who are likely to become infected because they are being treated with chemotherapy or radiation therapy before a bone marrow transplant (replacement of unhealthy spongy tissue inside the bones with healthy tissue). Fluconazole is in a class of antifungals called triazoles. It works by slowing the growth of fungi that cause infection.
Erlotinib Overview
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Erlotinib is used to treat certain types of non-small cell lung cancer that has spread to nearby tissues or to other parts of the body in patients who have already been treated with at least one other chemotherapy medication and have not gotten better. Erlotinib is also used in combination with another medication (gemcitabine [Gemzar]) to treat pancreatic cancer that has spread to nearby tissues or to other parts of the body and cannot be treated with surgery. Erlotinib is in a class of medications called kinase inhibitors. It works by blocking the action of an abnormal protein that signals cancer cells to multiply. This helps slow or stop the spread of cancer cells.
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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.