Drug Interaction Report
4 potential interactions and/or warnings found for the following 2 drugs:
- encorafenib
- Inrebic (fedratinib)
Interactions between your drugs
encorafenib fedratinib
Applies to: encorafenib, Inrebic (fedratinib)
Consumer information for this interaction is not currently available.
GENERALLY AVOID: Coadministration of encorafenib with a drug that is both a substrate as well as a moderate inhibitor of CYP450 3A4 may result in increased plasma concentrations of encorafenib and significantly decreased plasma concentrations of the other drug. Encorafenib itself is a substrate and a potent inducer of CYP450 3A4. When a single 50 mg dose of encorafenib (equivalent to 0.1 times the recommended dose) was administered with diltiazem, a moderate CYP450 3A4 inhibitor, encorafenib peak plasma concentration (Cmax) increased by 45% and systemic exposure (AUC) increased by 2-fold. Increased exposure to encorafenib may increase the risk of serious and life-threatening adverse effects such as hemorrhage, uveitis, QT prolongation, hepatotoxicity, dermatologic reactions, and new malignancies. Conversely, administration of a single 2 mg dose of the sensitive CYP450 3A4 substrate midazolam after repeated administration of encorafenib 450 mg once daily and binimetinib 45 mg twice daily resulted in decreased systemic exposure (AUC) and peak plasma concentration (Cmax) of midazolam by approximately 82% and 74%, respectively, compared to midazolam alone. Reduced plasma concentrations may potentially lead to decreased efficacy of the CYP450 3A4 substrate.
MANAGEMENT: Concomitant use of encorafenib with moderate CYP450 3A4 inhibitors that are also sensitive CYP450 3A4 substrates should generally be avoided. If coadministration is required, the manufacturer recommends reducing the encorafenib dose to one-half of the dose used prior to addition of the moderate CYP450 3A4 inhibitor. After the inhibitor has been discontinued for 3 to 5 elimination half-lives, the encorafenib dose that was taken prior to initiating the inhibitor may be resumed. If the concomitant medication also carries a risk of prolonging the QT interval, then obtaining more frequent electrocardiograms (ECGs) to monitor the QT interval may be advisable. Patients should be counseled to seek immediate medical attention if they experience symptoms that could indicate the occurrence of torsade de pointes such as dizziness, lightheadedness, syncope, palpitations, irregular heartbeat, and/or shortness of breath. The prescribing information for any concomitant medication should be consulted for further guidance and assessment of benefits versus risks of coadministration, as well as any dosage adjustments that may be required during coadministration and/or following the discontinuation of the potent CYP450 3A4 inducer.
Drug and food interactions
encorafenib food
Applies to: encorafenib
You should preferably avoid consumption of grapefruit and grapefruit juice while taking encorafenib. Grapefruit and grapefruit juice can significantly increase the blood levels of encorafenib. This may increase the risk of serious side effects such as bleeding complications, eye and vision problems, liver problems, irregular heart rhythm, and development of new skin cancers. Talk to your doctor if you have any questions or concerns. It is important to tell your doctor about all other medications you use, including vitamins and herbs. Do not stop using any medications without first talking to your doctor.
fedratinib food
Applies to: Inrebic (fedratinib)
Grapefruit juice can increase the blood levels of fedratinib. This may increase the risk of serious side effects such as Wernicke's encephalopathy, a potentially fatal condition of the brain associated with thiamine (vitamin B1) deficiency; low blood cell counts, which can lead to anemia, bleeding, and infections; severe diarrhea, nausea, and vomiting; problems in the liver or pancreas; and development of other cancers. You should avoid the consumption of grapefruit and grapefruit juice during treatment with fedratinib. You may take the medication with or without food, but taking it with a high-fat meal may help reduce nausea and vomiting. Talk to your doctor or pharmacist if you have questions on how to take this or other medications you are prescribed. It is important to tell your doctor about all other medications you use, including vitamins and herbs. Do not stop using any medications without first talking to your doctor.
Therapeutic duplication warnings
Therapeutic duplication is the use of more than one medicine from the same drug category or therapeutic class to treat the same condition. This can be intentional in cases where drugs with similar actions are used together for demonstrated therapeutic benefit. It can also be unintentional in cases where a patient has been treated by more than one doctor, or had prescriptions filled at more than one pharmacy, and can have potentially adverse consequences.
Multikinase inhibitors
Therapeutic duplication
The recommended maximum number of medicines in the 'multikinase inhibitors' category to be taken concurrently is usually one. Your list includes two medicines belonging to the 'multikinase inhibitors' category:
- encorafenib
- Inrebic (fedratinib)
Note: In certain circumstances, the benefits of taking this combination of drugs may outweigh any risks. Always consult your healthcare provider before making changes to your medications or dosage.
Drug Interaction Classification
| Highly clinically significant. Avoid combinations; the risk of the interaction outweighs the benefit. | |
| Moderately clinically significant. Usually avoid combinations; use it only under special circumstances. | |
| Minimally clinically significant. Minimize risk; assess risk and consider an alternative drug, take steps to circumvent the interaction risk and/or institute a monitoring plan. | |
| No interaction information available. |
Learn more
Further information
Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.
Check Interactions
To view an interaction report containing 4 (or more) medications, please sign in or create an account.
Save Interactions List
Sign in to your account to save this drug interaction list.