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Anticoagulation Clinic
Anticoagulation Clinic
The pharmacists at the Anticoagulation Clinic are committed to providing quality clinical and educational services that are timely and responsive to the needs of patients, families, other health professionals and the community.
Care and Treatment at Stanford
A Summary of Current Perspectives on Dental Procedures in Anticoagulated Patients[1][2][3]
Controversy still exists about whether dental treatments can be safely performed while the patient is taking warfarin therapy or if the warfarin needs to be reduced or stopped entirely.
- The majority of dental clinical literature does not support that the oral anticoagulant regimen be altered or discontinued before most dental procedures, including oral surgery.
- Current recommendations from the JADA based on review of published trial data are as the followings:
- No alteration of anticoagulation is necessary for INR that is in therapeutic range (INR 2-4), given that local hemostaticmeasures are used.
- Anticoagulation alteration is required if INR is >4.
- INR >5 is contraindicated for surgical procedure.
- The benefit and risk evaluation of bleeding vs. blood clots need to be carried out before making any decision regarding the anticoagulation therapy.
Algorithm for dental care of patients receiving anticoagulant therapy:
- Referred to a dental hospital or hospital based oral/maxillofacial surgeon when:
- Patient has one of the following medical conditions:
- Liver impairment and/or alcoholism
- Renal failure
- Thrombocytopenia, hemophilia or other disorder of hemostasis
- Patients is currently receiving a course of cytotoxic (chemotherapy) medication.
- Emergency Treatments such as open-fracture reduction or orthognathic surgery.
- Patient has one of the following medical conditions:
- For NON-urgent dental care of anticoagulated patients:
I. Patient assement prior to any dental procedure:
- Determined:
- Name of the primary care physician
- Reason for warfarin therapy
- Duration of therapy
- Frequency of monitoring
- Stability of therapy.
- Evaluate the dental treatment needs:
- Types of therapy required
- Potential for hemorrhage
- Presence of local factors that ↑potential for hemorrhage
- Block anesthesia requirement
- Number visits
- If a patient on a short course of warfarin therapy (≤ 6 months):
- For non-urgent elective treatment such as extractions or surgical procedures:
- can be delayed until the warfarin course has completed.
- Urgent elective treatment such as carious teeth or periodontal disease:
- Obtain an INR within 24 hours but not more than 72 hours before the procedure.
- Then, assess the safety of the dental treatment based on the INR.
- For non-urgent elective treatment such as extractions or surgical procedures:
- If patient on a long course of warfarin therapy (> 6months):
- Obtain an INR within 24 hours but not more than 72 hours before the procedure
- Then, assess the safety of the dental treatment based on the INR.
II. Evaluate safety of dental treatment for patients with Warfarin
a. Procedures involved low risk of bleeding:
- Examination, Radiographs, Study Models
- Safety profile based on INR:
- INR <1.5-3.5:
- Safe to proceed in a routine manner.
- INR >3.5:
- Can be safely performed with judicious use of local hemostatic measures** in many instances
- INR <1.5-3.5:
b. Procedures involved low-moderate risk of bleeding:
- Examples
- Simple restorative dentistry
- Supragingival prophylaxis
- Complex restorative dentistry
- Scaling and root planning
- Endodontics
- Safety profile based on INR:
- INR <1.5-3:
- Safe to proceed in a routine manner.
- INR >3:
- Not advised to do procedures. Need to refer to physician for adjustment of warfarin therapy.
- INR <1.5-3:
c. Procedures involved moderate risk of bleeding:
- Examples:
- Simple extraction up to 3 teeth
- Curettage
- Gingivoplasty
- Removal of single bony impaction
- Crown and bridge procedure
- Safety profile based on INR:
- INR <1.5-3.5:
- Can be safe to proceed with judicious use of local hemostatic measures in some instances.
- INR > 3.5:
- Not advised to do procedures. Need to refer to physician for adjustment of warfarin therapy.
- INR <1.5-3.5:
d. Procedures involved moderate-high risk of bleeding:
- Examples:
- Gingivectomy
- Apicoectomy
- Minor periodontal flap surgery
- Placement of single implant
- Safety profile based on INR:
- Not sufficient scientific data to draw a conclusion for any INR values.
- Not advised to do procedures. Need to refer to physician for adjustment of warfarin therapy and evaluate all factors for risk assessment.
e. Procedures involved high risk of bleeding:
- Examples:
- Full-mouth/Full-arch extractions
- Extensive flap surgery
- Extraction of multiple bony impactions
- Multiple implant placement
- Safety profile based on INR:
- Not sufficient scientific data to draw a conclusion for any INR values.
- Not advised to do procedures. Need to refer to physician for adjustment of warfarin therapy and evaluate all factors for risk assessment.
** Local hemostatic measures included:
- Gelatin sponges with silk sutures
- Systemic, irrigant, and mouthrinse forms of tranexamic acid
- Vasoconstrictors in local anesthetic
- Atraumatic surgical techniques
Three options for alteration of anticoagulation status:
- Option 1:
- After consult with physician → 2-3 day cessation of warfarin therapy → determine INR:
- If INR is unacceptable, defer an additional day → repeat INR → perform dental treatment only when INR is in an acceptable range → resume warfarin therapy on the evening of the same day of dental procedure.
- If INR is acceptable → perform dental treatment → resume warfarin therapy on the evening of the same day of dental procedure.
- After consult with physician → 2-3 day cessation of warfarin therapy → determine INR:
- Option 2:
- After consult with physician with an unacceptable INR:
- Discontinue warfarin therapy several days before surgery (or other dental treatment) and substitute heparin anticoagulant therapy or Low molecular weight heparin (LMWH).
- Heparin then can be discontinue 6-8 hours before surgery or Low molecular weight can be discontinued the day before surgery.
- Warfarin or heparin or LMWH can be readministered shortly (12-18 hours) after surgery.
- After consult with physician with an unacceptable INR:
- Option 3: (Not Recommended)
- After consult with physician, stop warfarin therapy for 4-5 days before performing dental treatment. Warfarin is then resumed after the dental treatment.
- Not recommended because ↑risk of thrombotic complications due to underlying disease.
Drug-to-Drug interaction considerations:
- Be cautious with antibiotic choice for endocarditis prophylaxis in patients who are on warfarin and undergoing dental treatment.
- A single Amoxicillin dose of 3 g dose given for endocardidis prophylaxis has not been shown to produce a clinically relevant interaction. Patient requiring a course of amoxicillin should be advised to be vigilant for any signs of ↑bleeding.
- Clindamycin does not interact with warfarin when given as a single dose for endocarditisprophylaxis.
- Clindamycin is restricted to specialist use for treatment and should not be used routinely for dental infections due to its serious side effects.
- There is a single case report of an interaction between warfarin and a course of clindamycin.
- Metronidazole interacts with warfarin and should be avoided whenever possible.
- If have to use metronidazole, warfarin dose may need to be ↓by 1/3 to ½. Consult with physician or anticoagulation clinic.
- Erythromycin interacts with warfarin unpredictably only in certain individuals. Patient should be advised to be vigilant for any signs of ↑bleeding.
- Be cautious with the choice of analgesic medications for pain control:
- Avoid NSAIDs or salicylates due to ↑risk of bleeding
- Careful monitor patient's INR if patient's is on COX-2 inhibitors (coxibs).
- May use Tylenol for short term pain reliever.
References:
- Herman W, Konzelman Jr. J, and Sutley S. Current perspectives on dental patients receiving coumarin anticoagulant therapy. JADA 1997 Mar;128:327-335.
- Jeske A, and Suchko G. Lack of a scientific basis for routine discontinuation of oral anticoagulation therapy before dental treatment. JADA 2003 Nov;134:1492-1497.
- Randall C. Surgical management of the primary carew dental patient on warfarin. North West Medicines Information Centre 2004 Mar:2-15.
For Patients
All patients must be referred by a Stanford doctor.
For blood draw only, contact us for a requisition order good for six months. We request that routine blood draws be done for patients who cannot be seen during the regular Oral Anticoagulation Clinic appointments.
PREPARE FOR YOUR APPOINTMENT
Your initial visit will be a one-hour education session about Warfarin use including side effects, drug and diet interactions, and clinic policies.
AFTER YOUR APPOINTMENT
- Have your INR checked if you have not seen us for a long time.
- Get updated labels once a month at the registration desk.
- Labels given to you at admitting must be attached to your samples/records.
- Keep an updated list of medications with you to review at your visits.
Call us to make an appointment
For Health Care Professionals
PHYSICIAN HELPLINE
Fax: 650-320-9443
Monday–Friday, 8 a.m.–5 p.m.
Stanford Health Care provides comprehensive services to refer and track patients, as well as the latest information and news for physicians and office staff. For help with all referral needs and questions, visit Referral Information.
You may also submit a web referral or complete a referral form and fax it to 650-320-9443 or email the Referral Center at ReferralCenter@stanfordhealthcare.org.
To request an appointment at the Anticoagulation Clinic, call 650-725-4932.
Patients must be referred by their Stanford Health Care primary care doctor.