Drug Interactions between afatinib and regorafenib
This report displays the potential drug interactions for the following 2 drugs:
- afatinib
- regorafenib
Interactions between your drugs
regorafenib afatinib
Applies to: regorafenib and afatinib
ADJUST DOSE: Coadministration with inhibitors of P-glycoprotein (P-gp) may increase the plasma concentrations of afatinib, which is a substrate of the efflux transporter. In study subjects, oral administration of the P-gp inhibitor ritonavir (200 mg twice daily) one hour before afatinib dosing resulted in a 48% increase in afatinib systemic exposure. There was no change in afatinib exposure when ritonavir was administered simultaneously with, or 6 hours after, the afatinib dose.
MANAGEMENT: Caution is advised if afatinib is used in combination with P-gp inhibitors. Patients should be monitored for potentially increased adverse effects such as diarrhea, which may lead to dehydration with or without renal impairment; cutaneous reactions including rash, erythema, and bullous, blistering, or exfoliating lesions; interstitial lung disease such as lung infiltration, pneumonitis, acute respiratory distress syndrome, and allergic alveolitis; hepatotoxicity, which may be life-threatening or fatal; keratitis characterized by acute or worsening eye inflammation, lacrimation, light sensitivity, blurred vision, eye pain, red eye, and/or ulceration; and left ventricular dysfunction. The manufacturer recommends reducing the daily dose of afatinib by 10 mg if not tolerated. The previous dose may be resumed after discontinuation of the P-gp inhibitor as tolerated.
References (1)
- (2013) "Product Information. Gilotrif (afatinib)." Boehringer Ingelheim
Drug and food interactions
regorafenib food
Applies to: regorafenib
ADJUST DOSING INTERVAL: Depending on the amount of fat, food may enhance the oral bioavailability of both regorafenib and its active metabolites, M-2 and M-5. In 24 healthy male subjects, administration of regorafenib with a high-fat meal (945 calories; 54.6 g fat) increased the mean systemic exposure (AUC) of regorafenib by 48% but decreased the mean AUC of M-2 and M-5 by 20% and 51%, respectively, compared to administration under the fasted state. In contrast, administration with a low-fat meal (319 calories; 8.2 g fat) increased the mean AUC of regorafenib, M-2 and M-5 by 36%, 40% and 23%, respectively, compared to administration during fasting.
GENERALLY AVOID: Coadministration with grapefruit juice may alter the pharmacokinetics of regorafenib and its active metabolites. The proposed mechanism is inhibition of CYP450 3A4-mediated first-pass metabolism in the gut wall by certain compounds present in grapefruit. The interaction has not been studied specifically with grapefruit juice, but has been reported with the potent CYP450 3A4 inhibitor, ketoconazole. In 18 healthy male study subjects, administration of a single 160 mg dose of regorafenib on day 5 of treatment with ketoconazole (400 mg daily for 18 days) resulted in a 33% increase in mean regorafenib systemic exposure (AUC) compared to administration of regorafenib alone. Additionally, there was a 93% decrease each in the mean AUC of the M-2 and M-5 metabolites. Both have been shown to have similar in vitro pharmacological activity and steady-state concentrations as regorafenib, thus the net clinical effect of these pharmacokinetic changes is unknown.
MANAGEMENT: To ensure optimal oral absorption, regorafenib should be administered with a low-fat breakfast that contains less than 30% fat. Examples of a low-fat breakfast include: 2 slices of white toast with 1 tablespoon of low-fat margarine and 1 tablespoon of jelly, plus 8 ounces of skim milk (319 calories; 8.2 g fat); or 1 cup of cereal, 8 ounces of skim milk, 1 slice of toast with jam, apple juice, and 1 cup of coffee or tea (520 calories; 2 g fat). Patients should be advised to avoid consuming grapefruit or grapefruit juice during treatment with regorafenib.
References (1)
- (2012) "Product Information. Stivarga (regorafenib)." Bayer Pharmaceutical Inc
afatinib food
Applies to: afatinib
ADJUST DOSING INTERVAL: Food may reduce the oral bioavailability of afatinib. According to the product labeling, administration of afatinib with a high-fat meal decreased peak plasma concentration (Cmax) by 50% and systemic exposure (AUC) by 39% compared to administration in the fasted state.
MANAGEMENT: Afatinib should be taken at least 1 hour before or 2 hours after a meal.
References (1)
- (2013) "Product Information. Gilotrif (afatinib)." Boehringer Ingelheim
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:
- afatinib
- regorafenib
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.
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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