Coumadin and Vfend

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.

Using warfarin together with voriconazole can cause you to bleed more easily. You may need a dose adjustment in addition to testing of your prothrombin time or International Normalized Ratio (INR). Call your doctor promptly if you have any unusual bleeding or bruising, vomiting, blood in your urine or stools, headache, dizziness, or weakness. 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 CLOSELY: Coadministration with voriconazole may significantly increase the plasma concentrations and hypoprothrombinemic effect of warfarin. The mechanism is voriconazole inhibition of CYP450 2C9, 2C19 and 3A4, the isoenzymes responsible for the metabolic clearance of racemic warfarin. In healthy volunteers, coadministration of voriconazole (300 mg every 12 hours for 12 days) with warfarin (30 mg single dose on day 7) significantly increased maximum prothrombin time by approximately 2 times that observed with placebo. Prothrombin times were still increased by a mean value of 5.4 seconds 144 hours post warfarin dose following coadministration with voriconazole.

MANAGEMENT: Patients should be closely monitored during concomitant therapy with warfarin and voriconazole. The INR should be checked frequently and warfarin dosage adjusted accordingly, particularly following initiation, discontinuation or change of dosage of voriconazole in patients who are stabilized on their anticoagulant 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. The same precaution may be applicable during therapy with other oral anticoagulants, although clinical data are lacking.

Coumadin

Generic Name: warfarin

Brand name: Coumadin, Jantoven

Synonyms: n.a.

What is Coumadin?

Vfend

Generic Name: voriconazole

Brand name: Vfend, Vfend

Synonyms: Vfend Injection

What is Vfend?