Dental extraction in a patient taking warfarin with an INR of 3.6
A 67-year-old man with permanent atrial fibrillation takes warfarin 5 mg daily. He attends for extraction of a grossly carious mandibular right first molar and a retained root. His INR today is 3.6. He reports that an extraction 2 years ago bled for about 6 hours and required a hospital visit. He also takes amiodarone 200 mg daily, which was started 6 weeks ago, and his most recent INR before today was 2.8. Blood pressure is 150/90 mmHg, platelet count is normal, and he has no bruising or active bleeding. He is in pain, has a buccal swelling, and wants the teeth removed today because he is travelling abroad in 3 weeks. The clinic has local anaesthetic, sutures, tranexamic acid mouthwash, and access to his cardiologist by phone.
1. Do you proceed with extraction today? Give your reasoning with reference to his INR, medication history, and bleeding history.
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I would not proceed with elective extraction today. The INR is 3.6, which is above the usual therapeutic range for atrial fibrillation (2.0–3.0), and he has two features that increase bleeding risk: a previous extraction that bled for 6 hours and a recent start of amiodarone.
Amiodarone inhibits warfarin metabolism and commonly raises the INR; the jump from 2.8 to 3.6 after starting amiodarone is consistent with that interaction. The correct action is to contact his cardiologist or anticoagulation service, arrange a warfarin dose review, and recheck the INR before any elective extraction. Warfarin should not be stopped abruptly without cardiology input because of stroke risk.
The buccal swelling and pain do not automatically make this an emergency. If there is no spreading infection, airway compromise, or uncontrolled pain, the extraction can wait a few days until the INR is safer. If infection is spreading, he needs urgent medical assessment and possibly admission, not a routine clinic extraction.
2. If the tooth must be removed within the next few days, outline a safe plan including local haemostatic measures and communication.
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A safe plan requires coordination rather than a single clinic decision.
- Communicate with cardiology or the anticoagulation service before changing anything. Ask whether the warfarin dose can be adjusted to bring the INR to a safer level, usually 3.0 or below for a simple extraction, and recheck the INR within 24–48 hours of the procedure.
- Do not stop warfarin routinely for a simple extraction; the stroke risk outweighs the bleeding risk in most patients with atrial fibrillation. Bridging is not usually needed for dental extraction.
- Plan the appointment for early in the day, with time to manage bleeding, and confirm that the INR result is recent.
- Local measures: use an appropriate local anaesthetic, avoid excessive trauma, place sutures, apply pressure with a gauze pack, and consider a haemostatic plug. Prescribe tranexamic acid 5% mouthwash to use after the procedure according to local protocol, and give clear instructions to return if bleeding persists.
- Analgesia: avoid NSAIDs; use paracetamol.
If the INR cannot be brought into a safer range and the tooth is causing recurrent infection, hospital-based extraction with haematology support may be safer than repeated clinic attempts.