Anticoagulants or Antiplatelet Drugs

Question 1

How do anti platelet drugs interfere with clotting?

Answer 1

They interfere with platelet aggregation and impair primary haemostatsis

Question 2

How do anticoagulant drugs interfere with clotting?

Answer 2

They inhibit the production or activity of clotting factors that are required for the coagulation cascade and impair secondary haemostats

Question 3

What is the function of fibrin in clotting ?

Answer 3

stabilises the primary platelet plug by cross linking the platelets to each other and to the damaged blood vessel wall to prevent further blood loss (secondary haemostasis)

Question 4

What is thrombosis ?

Answer 4

when a blood clot blocks a blood vessel and can result in heart attack, pulmonary embolism or stroke

Question 5

How does Dabigatran work ?

Answer 5

Directly inhibits coagulation factor thrombin

Question 6

How does apixiban, rivaroxaban and edoxaban work ?

Answer 6

inhibit Factor 10a, inhibits the conversion of prothrombin to thrombin stopping the production go the fibrin clot

These drugs have a more predictable lever of anticoagulation

Question 7

What are dental procedures unlikely to because bleeding ?

Answer 7

• local anaesthetic by infiltration, or block
• BPE
• supra gingival scaling
• restorations with supra gingival margins
• Endodontics
• impressions and other prosthetic procedures

Question 8

What are dental procedures that have low risk of post op bleeding ?

Answer 8

• simple extractions
• incision and drainage of intra-oral swellings
• 6 point pocket charts
• root surface debridement
• restorations with subgingival margins

Question 9

What are dental procedures that have high risk of post op bleeding ?

Answer 9

• complex extractions
• adjacent extractions that will cause a large wound
• Flap raising procedures
• Biopsies

Question 10

How does renal failure increase bleeding risk?

Answer 10

it is associated with platelet dysfunction

Question 11

How does liver disease increase bleeding risk?

Answer 11

• reduced clotting factors
• reduced platelet numbers

Question 12

What over the counter medications can increase bleeding risk?

Answer 12

• aspirin
• NSAIDs

Question 13

What are local haemostasis measures to reduce risk of bleeding?

Answer 13

• damp guaze and apply firm pressure for 20- 30 minutes
• Use LA with vasoconstrictor
• pack with oxidised cellulose matrix - e.g. surgicel
• Suture
• Diathermy

Question 14

What is a contraindication of surgicel?

Answer 14

Avoid use on lower 8s as it is acidic and may because damage to the IAN

Question 15

What is the advice given for patients taking a DOAC requiring treatment at low risk of bleeding complications?

Answer 15

• treat without interrupting anticoagulant medication
• plan treatment early in the day to allow monitoring and management of bleeding complications
• limit treatment area - perform minimal treatment then assess bleeding before continuing
• use local haemostatic measures to achieve haemostasis

Question 16

What is the advice for a patient taking a DOAC requiring treatment at high risk of bleeding complications?

Answer 16

• Discuss with cardiologist
• may advise them to miss or delay their morning dose on the day of their dental treatment
• REMEMBER to advice them when to restart medication
• plan treatment early in the day to allow monitoring and management of bleeding complications
• stage treatments
• use local haemostats measures to achieve haemostasis

Question 17

What DOACs are taken once daily?

Answer 17

Rivaroxaban or edoxaban

Question 18

What DOACs are taken twice daily?

Answer 18

Apixaban or dabigatran

Question 19

When can patients taking rivaroxaban or edoxaban restart their medication ?

Answer 19

if patient takes medication in the morning - restart 4 hours after haemostasis has been achieved then take the next day dose as normal

if patient takes medication in the evening - take medication as normal as long as it is 4 hours after haemostasis has been achieved and continue as normal the following day

Question 20

When can patients taking apixaban or dabigatran restart medication having missed their morning dose?

Answer 20

• take their evening disease as usual as long as it is 4 hours after haemostasis has been achieved then continue the medication as normal

Question 21

What is the INR value equivalent to an average patient ?

Answer 21

1

Question 22

What is the INR level advised for treatment ?

Answer 22

<4

Question 23

When should you check a patients INR before a treatment ?

Answer 23

No more than 24 hours before unless the patient is stable then 72 hours before

Question 24

What is considered a stable patient on warfarin

Answer 24

• no readings greater than 4 in the last 2 months
• doesn’t require weekly monitoring

Question 25

What anticoagulant is used in patients that require renal dialysis?

Answer 25

Heparin

Question 26

What is the guidance for treating a patient on a prophylactic (low) dose of LMW heparin ?

Answer 26

treat without interruption of medication

Question 27

What is the guidance for patients taking single or dual anti-platelet drugs?

Answer 27

treat without interrupting medication

• be aware the patient will have prolonged bleeding time and this will influence treatment time
• stage treatment
• use local haemostatic measures

Question 28

What is the guidance for patients taking both anti-platelet and anticoagulation medication?

Answer 28

Consult with the prescribing clinician

some patients may only be on drug combinations for a few weeks so it is possible to delay dental treatment

Question 29

What effect can dental medications have on patients taking anti-platelet or anti-coagulation medication?

Answer 29

Dental medication can interact with anticoagulant ir anti platelet drugs and affect the coagulation levels