Drug interactions between Tafinlar and Zelboraf
Interactions between your drugs
vemurafenib ↔ dabrafenib
Applies to:Zelboraf (vemurafenib) and Tafinlar (dabrafenib)
Consumer information for this interaction is not currently available.
MONITOR: Coadministration with dabrafenib may decrease the plasma concentrations of drugs that are primarily metabolized by CYP450 3A4 and/or 2C9. Dabrafenib has been found in vitro to be an inducer of these isoenzymes. Onset of induction is likely to occur after 3 days of repeat dosing with dabrafenib; however, transient inhibition of CYP450 isoenzymes may be observed during the first few days of treatment. In 12 study subjects, administration of the CYP450 3A4 probe substrate midazolam following repeat doses of dabrafenib 150 mg twice daily for 15 days reduced midazolam peak plasma concentration (Cmax) by 61% and systemic exposure (AUC) by 74%. When a single 15 mg dose of warfarin was coadministered similarly with dabrafenib, the AUC of S(-) warfarin decreased by 37% and that of R(+) decreased by 33%. S(-) warfarin, the biologically more active enantiomer, is primarily metabolized by CYP450 2C9, while R(+) warfarin is a substrate of CYP450 3A4 and 1A2.
MANAGEMENT: Caution is advised when dabrafenib is prescribed with drugs that undergo metabolism by CYP450 3A4 and/or 2C9. Dosage adjustments as well as clinical and laboratory monitoring may be appropriate for some drugs whenever dabrafenib is added to or withdrawn from therapy. Significantly reduced plasma concentrations and loss of efficacy may occur with sensitive substrates of CYP450 3A4 or 2C9 such as hormonal contraceptives, immunosuppressants (cyclosporine, everolimus, sirolimus, tacrolimus), ivacaftor, and warfarin-type anticoagulants. Alternatives to these medications should be considered if possible.
- "Product Information. Tafinlar (dabrafenib)." GlaxoSmithKline, Research Triangle Park, NC.
- Cerner Multum, Inc. "UK Summary of Product Characteristics." O 0
Drug and food interactions
Applies to: Tafinlar (dabrafenib)
Food may delay and reduce the absorption of dabrafenib, which may lead to lower blood levels of the medication and possibly reduced effectiveness. You should take dabrafenib at least 1 hour before or 2 hours after a meal.
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.
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:
- dabrafenib (active ingredient in Tafinlar (dabrafenib))
- vemurafenib (active ingredient in Zelboraf (vemurafenib))
Note: The benefits of taking this combination of medicines may outweigh any risks associated with therapeutic duplication. This information does not take the place of talking to your doctor. Always check with your healthcare provider to determine if any adjustments to your medications are needed.
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 information available.|
Do not stop taking any medications without consulting your healthcare provider.
Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.