Anticoagulation and Antiplatelet Drugs Flashcards
What drugs are NOT safe with NOACs (3)?
- All antibiotics safe EXCEPT MACROLIDES (erythromycin, clarithromycin).
- NSAIDs prolong action and inhibit platelets - avoid.
- avoid carbamazepine.
What is clopidogrel? What 2 medications is it contraindicated with?
Erythromicin and fluconazole may reduce efficacy.
What drugs must be avoided when patient is on antiplatelets?
- NSAIDS - may reduce effect of aspirin.
-Carbamazepine/omeprazole may reduce efficacy
What are the guidelines for higher risk procedure in patients taking NOACs? What about low risk procedure?
- Higher risk: miss morning dose (if twice daily) OR delay morning dose (if once daily - restart after thrombus has formed).
- Low risk: no NOAC change.
- early in the day + week, limit initial treatment, local hemostatic measures etc..
What are the guidelines for dental procedures likely to cause bleeding in patients taking Warfarin (5)?
- INR must be checked no more than 72 hours prior, ideally 24 hours.
- if INR below 4 = proceed as normal.
- early in the day and the week.
- Local hemostatic measures
- Post-op instructions + contact number.
What is the mode of action of NOACs
Prevent the effect of Factor X
List 5 “caution” dental procedures.
- Biopsies.
- Periodontal Surgery.
- Extraction.
- Implants.
- Minor oral surgery.
What is the coagulation cascade?
a series of steps in response to bleeding caused by tissue injury, where each step activates the next and ultimately produces a blood clot.
Give 4 named examples of NOACs and how often they are administered.
- Apixaban –> twice daily
- Rivaroxiban –> once
- Edoxaban –> once
- Dabigatran –> once
(DARE)
Dental care of a patient on DUAL ANTIPLATELET therapy WITHOUT ASPIRIN.
- contact DOCTOR - likely stop one of the drugs for 7 DAYS prior to procedure.
Give two examples of NSAIDs.
ibuprofen, diclofenac
What are the two major types of oral anticoagulants?
- Warfarin
- Novel oral anticoagulants (NOACs).
How long must a NOAC patient be kept post-extraction to assess bleeding?
at least 20 minutes.
Name 3 standard antiplatelet medicines.
- aspirin.
- clopidogrel.
- dipyridamole.
Can IDB be done on NOAC patients?
Yes
What is the function/ mode of action of warfarin?
- Vitamin K antagonist, affect the synthesis of CLOTTING FACTORS 2, 7, 9 and 10.
What is ticagrelor? What medication is it contraindicated with?
- Clarithromycin may increase the effect.
List 5 indications for anticoagulation.
atrial fibrillation, deep venous thrombosis, mechanical valve disease, heart valve disease, thrombophilia.
How often must the INR be checked?
- Every 4-8 weeks if STABLE, more often if unstable.
What medications (3) must be avoided in patients on Warfarin?
- NSAIDs (ex. ibuprofen, diclofenac).
- Aspirin (as an analgesic).
- Azole antifungal drugs (fluconazole, itraconazole, miconazole).
What is the mode of action of antiplatelets?
Inhibit platelet aggregation and thrombus formation.
What is the onset of Warfarin? Why is it important?
SLOW onset over 3 DAYS –> initial period of HYPERCOAGULABILITY.
THUS IF PATIENT IS ASKED TO STOP WARFARIN BEFORE PROCEDURE WHEN THEY RESTART IT WILL LEAD TO HYPERCOAGULATION AND CAN PUT PATIENT AT RISK OF PULMONARY EMBOLISM.
What do all patients on Warfarin carry?
Recording anticoagulant booklet.
What is the biggest warfarin hazard? How can it be reversed?
- HAEMORRHAGE - 1% per annum risk of serious bleed-
- 25% of serious bleeds are FATAL.
- Rapid reversal of anticoagulation with vitamin K injection.
What are 3 advantages of NOACs?
- Predictable bioavailability (no need to monitor action).
- Rapid onset of action (within hour of dose).
- short duration of action (effect lost within the day).
List 5 “safe” dental procedures.
- Hygiene therapy
- Removable prosthodontics
- Endodontics
- Orthodontics.
- Restorative dentistry (+ crowns, bridges)
What is the onset of NOACs/
rapid onset - 1 hour
Dental care of a patient on aspirin?
- DO NOT interrupt medication.
What are the two types of injectable anticoagulants? How are they administered? Are there any dental considerations?
- Unfractionated heparin: infusion, slow/stop medication if extraction is needed.
- low molecular weight heparin: subcutaneous injection once daily, no dental considerations.
What are the 3 types of ANTITHROMBOTIC medication?
- Injectable anticoagulants
- Oral anticoagulants
- Antiplatelets
Dental care of a patient on DUAL ANTIPLATELET therapy WITH ASPIRIN.
- DO NOT interrupt medication.
- likely prolonged bleeding.
How is the body’s response to Warfarin measured? What are typical values?
- Using INTERNATIONAL NORMALIZED RATION (INR).
- NORMAL: 2-3.
- 3-4 in prosthetic valves OR higher risk of DVT/PE.
Name 3 forms of local hemostatic measures.
- Cellulose sponge.
- Sutures.
- Local anesthetic.
