Is there any evidence in the literature for interactions between high-dose omega-3 fish oil and warfarin?

There are a few isolated reports that a furthering of anti-coagulant effects can occur when omega-3 supplementation is added onto the use of warfarin in selected patients. It has been advised that clinicians be aware of such potential interactions including increased bleeding times. It is noted that dietary intakes of DHA plus EPA of approximately 1000 mg are common in Japan.