Skip to main content

Drug Interactions between Fulvicin U/F and lapatinib

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

Edit list (add/remove drugs)

Interactions between your drugs

Moderate

griseofulvin lapatinib

Applies to: Fulvicin U/F (griseofulvin) and lapatinib

MONITOR: Coadministration with inducers of CYP450 3A4 may decrease the plasma concentrations of lapatinib, which is primarily metabolized by the isoenzyme. In 24 healthy subjects, administration of a single 250 mg oral dose of lapatinib following treatment with the potent CYP450 3A4 inducer carbamazepine (100 mg twice daily for 3 days, then 200 mg twice daily for 17 days) decreased mean lapatinib peak plasma concentration (Cmax) and systemic exposure (AUC) by 59% and 72%, respectively, compared to administration of lapatinib alone. The interaction has not been studied with other, less potent inducers.

MANAGEMENT: The potential for diminished pharmacologic effects of lapatinib should be considered during coadministration with CYP450 3A4 inducers. Pharmacologic response to lapatinib should be monitored more closely whenever a CYP450 3A4 inducer is added to or withdrawn from therapy, and the lapatinib dosage adjusted as necessary.

References

  1. (2023) "Product Information. Tykerb (lapatinib)." Novartis Pharmaceuticals
  2. (2022) "Product Information. Tykerb (lapatinib)." Novartis Pharmaceuticals Canada Inc
  3. (2022) "Product Information. Tyverb (lapatinib)." Novartis Pharmaceuticals UK Ltd
  4. (2022) "Product Information. Tykerb (laPAtinib)." Novartis Pharmaceuticals Australia Pty Ltd
  5. Smith DA, Koch KM, Arya N, Bowen CJ, Herendeen JM, Beelan A (2009) "Effects of ketoconazole and carbamazepine on lapatinib pharmacokinetics in healthy subjects." Br J Clin Pharmacol, 67, p. 421-6
View all 5 references

Switch to consumer interaction data

Drug and food interactions

Moderate

griseofulvin food

Applies to: Fulvicin U/F (griseofulvin)

MONITOR: Isolated case reports have suggested that the ingestion of alcohol during griseofulvin therapy may rarely cause disulfiram-like reactions, flushing, tachycardia, or increased effects of alcohol. The mechanism is unknown.

MANAGEMENT: Patients should be advised of the possibility of increased adverse effects or a disulfiram-like reaction.

References

  1. "Product Information. Grifulvin V (griseofulvin)." Ortho McNeil Pharmaceutical
  2. (2002) "Product Information. Fulvicin P/G (griseofulvin)." Schering Corporation
  3. Cerner Multum, Inc. "Australian Product Information."

Switch to consumer interaction data

Moderate

lapatinib food

Applies to: lapatinib

GENERALLY AVOID: Grapefruit juice may increase the plasma concentrations of lapatinib. The proposed mechanism is inhibition of CYP450 3A4-mediated first-pass metabolism in the gut wall by certain compounds present in grapefruits.

ADJUST DOSING INTERVAL: Food can significantly increase the oral bioavailability of lapatinib. According to the manufacturer, lapatinib peak plasma concentration (Cmax) was approximately 2.5- and 3-fold higher and systemic exposure (AUC) 3- and 4-fold higher when administered with a low fat meal (5% fat; 500 calories) or with a high-fat meal (50% fat; 1000 calories), respectively, compared to fasting. Dividing the daily dose also resulted in an approximately 2-fold higher systemic exposure at steady state compared to the same total dose administered once daily.

MANAGEMENT: Patients treated with lapatinib should preferably avoid the consumption of grapefruit or grapefruit juice. The manufacturer recommends that lapatinib be administered at least one hour before or one hour after a meal. The lapatinib dose is administered once daily and should not be divided.

References

  1. (2007) "Product Information. Tykerb (lapatinib)." Novartis Pharmaceuticals

Switch to consumer 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.

See also

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.

Medical Disclaimer