Drug Interactions between lapatinib and Protonix IV
This report displays the potential drug interactions for the following 2 drugs:
- lapatinib
- Protonix IV (pantoprazole)
Interactions between your drugs
pantoprazole lapatinib
Applies to: Protonix IV (pantoprazole) and lapatinib
MONITOR: Nonclinical data indicate that the solubility of lapatinib is pH-dependent. Therefore, long-term suppression of gastric acid secretion by H2-receptor antagonists or proton pump inhibitors may reduce lapatinib systemic exposure. In study subjects, coadministration with the proton pump inhibitor esomeprazole (40 mg once daily for 7 days) decreased lapatinib exposure by an average of 27% (range 6% to 49%). This effect decreases with increasing age from approximately 40 to 60 years. The clinical significance is unknown.
MANAGEMENT: Caution may be advisable if lapatinib is used in combination with H2-receptor antagonists or proton pump inhibitors. Patients should be monitored for potentially reduced therapeutic response to lapatinib.
References (2)
- Cerner Multum, Inc. "UK Summary of Product Characteristics."
- (2007) "Product Information. Tykerb (lapatinib)." Novartis Pharmaceuticals
Drug and food interactions
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
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.
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