Drug Interactions between encorafenib and guanfacine
This report displays the potential drug interactions for the following 2 drugs:
- encorafenib
- guanfacine
Interactions between your drugs
guanFACINE encorafenib
Applies to: guanfacine and encorafenib
Consumer information for this interaction is not currently available.
ADJUST DOSE: Coadministration with inducers of CYP450 3A4 may significantly decrease the plasma concentrations of guanfacine, which is primarily metabolized by the isoenzyme. Rifampin, a potent CYP450 3A4 inducer, has been reported to decrease guanfacine peak plasma concentration (Cmax) and systemic exposure (AUC) by 54% and 70%, respectively. A computer simulation suggests that efavirenz, a moderate CYP450 3A4 inducer, would reduce guanfacine Cmax and AUC by a similar magnitude.
MANAGEMENT: Close monitoring and dosage adjustment should be considered when guanfacine is administered with potent and moderate CYP450 3A4 inducers. For extended-release guanfacine, some manufacturers recommend increasing the dosage up to double the recommended level when initiating therapy in patients who are already receiving a CYP450 3A4 inducer. Further dosage adjustments may be required based on patient tolerance and response. If a CYP450 3A4 inducer is added to existing guanfacine therapy, the guanfacine dosage may be increased up to double the recommended level over 1 to 2 weeks. The dosage should be decreased to the recommended level over 1 to 2 weeks following discontinuation of the CYP450 3A4 inducer.
References
- Kiechel JR, Lavene D, Guerret M, Comoy E, Godin M, Fillastre JP (1983) "Pharmacokinetic aspects of guanfacine withdrawal syndrome in a hypertensive patient with chronic renal failure." Eur J Clin Pharmacol, 25, p. 463-6
- Cerner Multum, Inc. "UK Summary of Product Characteristics."
- (2009) "Product Information. Intuniv (guanfacine)." Shire US Inc
Drug and food interactions
guanFACINE food
Applies to: guanfacine
Avoid consuming grapefruit or grapefruit juice during treatment with guanFACINE, as it may increase blood levels and effects of the medication. This may cause blood pressure to fall excessively, especially when you rise from a sitting or lying position. The risk of other side effects such as drowsiness, dizziness, lightheadedness, fainting, headache, palpitations, and heart rate changes may also increase. Additionally, you should avoid or limit the use of alcohol while being treated with guanFACINE. Combining the medication with alcohol can intensify sedative and blood pressure lowering effects, which may increase the risk of falls and injury. Avoid driving or operating hazardous machinery until you know how the medication affects you, and use caution when getting up from a sitting or lying position. If you are using a long-acting or extended-release formulation of the medication, make sure you do not take it with a high-fat meal. Doing so results in increased absorption and elevated blood levels of the medication. Talk to your doctor or pharmacist if you have any questions or concerns.
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.
Therapeutic duplication warnings
No warnings were found for your selected drugs.
Therapeutic duplication warnings are only returned when drugs within the same group exceed the recommended therapeutic duplication maximum.
See also
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. |
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.