Vitamin K antagonist (oral anticoagulant)
Warfarin overdose: signs, risks and what to do
Overdose of Warfarin (Warfarin) is uncommon at the standard 1mg, 2mg, 2.5mg, 3mg, 4mg, 5mg dose but can occur with accidental double dosing, intentional misuse or interactions. Knowing the signs and the right response is part of safe use, especially in households where Warfarin is shared or stored within reach of children.
Recognising overdose
Overdose typically presents as exaggerated versions of the medication's known side effects. With Warfarin, that can include severe hypotension, marked dizziness, confusion, persistent vomiting, prolonged visual disturbances, syncope, or, in extreme cases, cardiovascular instability. Symptom severity scales with the amount taken and with co-ingestion of alcohol or interacting drugs.
Immediate action
Suspected overdose is a medical emergency. Stop further dosing immediately and contact emergency services or your local poison control. Do not induce vomiting unless instructed by a healthcare provider. According to the prescribing information, no specific antidote exists for most Vitamin K antagonist (oral anticoagulant) agents — supportive care is the standard approach.
Frequently asked questions
How much Warfarin is too much? ▾
Any single dose above the maximum 1mg, 2mg, 2.5mg, 3mg, 4mg, 5mg prescribed strength, or any second dose taken inside the recommended interval, qualifies as a potential overdose risk and warrants caution. The exact threshold for symptoms varies between people.
Is Warfarin overdose deadly? ▾
Death from Warfarin overdose is rare with the active ingredient Warfarin alone. Risk is highest when combined with alcohol, with other interacting medications, or in people with underlying cardiovascular disease. Any suspected overdose should be evaluated urgently regardless.
Products containing Warfarin
More on Warfarin
- With alcoholWarfarin and alcohol — is it safe to drink?
- With foodShould Warfarin be taken with food?
- Side effectsWarfarin side effects: common, rare and warning signs
- Dosage guideWarfarin dosage guide: how much to take and when
- OnsetHow fast does Warfarin start working?
- DurationHow long does Warfarin last?
The information on this website is provided for reference and educational purposes only. It does not replace consultation with a qualified healthcare professional.