Does coumadin (warfarin) have rat poison?

See below: Coumadin (warfarin) is rat poison.

Yes: For many years Coumadin (warfarin) was used as rat poison. Excessive amounts would lead to uncontrolled bleeding in rats. This is why we carefully monitor people on the medication.

Basically yes: Warfarin (coumadin (warfarin) is a brand name) had been used in some rat poisons in the past to cause rats to suffer fatal hemorrhages. In most cases its use has been replaced by more lethal rodenticides. Warfarin can cause serious bleeding in patients as well - and therefore its use must be monitored closely by the pt/inr blood test.