Skip to main content

Drug Interactions between guanfacine and tovorafenib

This report displays the potential drug interactions for the following 2 drugs:

Edit list (add/remove drugs)

Interactions between your drugs

Moderate

guanFACINE tovorafenib

Applies to: guanfacine and tovorafenib

Consumer information for this interaction is not currently available.

MONITOR: Coadministration with inducers of CYP450 3A4 may 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: The possibility of diminished therapeutic response to guanfacine should be considered during coadministration with CYP450 3A4 inducers. Pharmacologic response to guanfacine should be monitored more closely whenever a CYP450 3A4 inducer is added to or withdrawn from therapy, and the dosage adjusted as necessary.

References

  1. 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
  2. Cerner Multum, Inc. "UK Summary of Product Characteristics."
  3. (2009) "Product Information. Intuniv (guanfacine)." Shire US Inc

Drug and food interactions

Major

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.

Switch to professional interaction data

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.


Report options

Loading...
QR code containing a link to this page

Drug Interaction Classification

These classifications are only a guideline. The relevance of a particular drug interaction to a specific individual is difficult to determine. Always consult your healthcare provider before starting or stopping any medication.
Major Highly clinically significant. Avoid combinations; the risk of the interaction outweighs the benefit.
Moderate Moderately clinically significant. Usually avoid combinations; use it only under special circumstances.
Minor 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.
Unknown No interaction information available.

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.