Jantoven and Vemurafenib

In the database of official manuals used in the service creation an interaction registered by statistical results of studies was found, which can either lead to negative consequences for the patient health or strengthen a mutual positive effect. A doctor should be consulted to address the issue of joint drug administration.

Vemurafenib may increase the blood levels and effects of warfarin. You may need a dose adjustment or more frequent monitoring of your prothrombin time or INR by your doctor to safely use both medications. Let your doctor know if your condition changes or you experience unusual bleeding or bruising. It is important to tell your doctor about all other medications you use, including vitamins and herbs. Do not stop using any medications without first talking to your doctor.

MONITOR: Coadministration with vemurafenib may increase the plasma concentrations of warfarin. The proposed mechanism is vemurafenib inhibition of CYP450 2C9, the isoenzyme responsible for the metabolic clearance of the biologically more active S(-) enantiomer of warfarin. In an in vivo phenotypic cocktail drug-drug interaction study in patients with cancer, S(-) warfarin systemic exposure (AUC) increased by 18% when a single dose of the CYP probe substrate cocktail was administered following treatment with vemurafenib 960 mg twice daily for 15 days.

MANAGEMENT: Caution is advisable if warfarin is used in combination with vemurafenib. The INR should be checked frequently and warfarin dosage adjusted accordingly, particularly following initiation or discontinuation of vemurafenib in patients who are stabilized on their warfarin regimen. Patients should be advised to promptly report any signs of bleeding to their physician, including pain, swelling, headache, dizziness, weakness, prolonged bleeding from cuts, increased menstrual flow, vaginal bleeding, nosebleeds, bleeding of gums from brushing, unusual bleeding or bruising, red or brown urine, or red or black stools.

Jantoven

Generic Name: warfarin

Brand name: Coumadin, Jantoven

Synonyms: n.a.

What is Jantoven?

Vemurafenib

Generic Name: vemurafenib

Brand name: Zelboraf

Synonyms: n.a.

What is Vemurafenib?