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Coumadin Toxicity
It is possible to develop Coumadin toxicity if you are not being monitored regularly. Careful monitoring, using certain blood tests, can help your healthcare provider determine if your dosage needs to be adjusted. Toxicity can result in many serious problems; taking too little of the medication can lead to blood clots and strokes, while taking too much Coumadin can lead to dangerous internal bleeding.
Coumadin® (warfarin sodium) is a prescription anticoagulant medication. It is often called a "blood thinner," although it does not really thin the blood. While Coumadin certainly can be a life-saving medication, it can cause significant toxicity. While careful monitoring can limit the toxicity of Coumadin, the unpredictable nature of this medication makes it impossible to entirely limit the potential for toxic effects.
The most significant, serious side effect of Coumadin is bleeding. This can include obvious bleeding, such as vomiting of blood, nosebleeds, or bright red blood in the stool, or bleeding that is less obvious, such as internal bleeding. Signs of bleeding due to Coumadin toxicity include:
- Easy bruising
- Cuts or scrapes that are slow to stop bleeding
- Signs of gastrointestinal bleeding, such as:
- Black, tarry stools
- Bright red blood in the stool
- Vomiting of blood
- Signs of bleeding in the brain (such as hemorrhagic stroke), including:
- Vision or speech changes
- Weakness or numbness in an arm or leg
- Severe headache.
(Click Coumadin Side Effects for more information.)
Written by/reviewed by: Kristi Monson, PharmD; Arthur Schoenstadt, MD
Last reviewed by: Kristi Monson, PharmD