SDCEP anticoagulants and antiplatelets

Question 1

how do you assess bleeding risk for a patient taking anticoagulant or anti platelet medication?

Answer 1

• assess likeliness of bleeding peri/post op and whether it has low or higher risk bleeding complications
• ask pt about the medication they take pre-op
• ask if their drug treatment is long term or for a limited time
• ask pt about any medical conditions they have
• ask pt about their bleeding history

Question 2

what is the guidance for treating a pt on anticoagulant/anti-platelet medication for a procedure unlikey to cause bleeding?

Answer 2

treat the patient following standard procedures, taking care to avoid causing bleeding

Question 3

how would you manage a pt on time limited anticoagulation/anti-platelet medication for a procedure that is likely to cause bleeding?

Answer 3

delay non-urgent, invasive procedures where possible

Question 4

give a general summary of the purpose of anticoagulation/anti-platelet drugs

Answer 4

agents that reduce the ability of blood to form clots or coagulate

Question 5

briefly describe primary haemostasis

Answer 5

Platelets within the blood become activated locally, resulting in an increased tendency to adhere to each other and to damaged blood vessel endothelium

Question 6

briefly describe secondary haemostasis

Answer 6

Fibrin 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

Question 7

what is fibrin?

Answer 7

the activated cross-linking form of fibrinogen

Question 8

how do anti-platelet drugs interfere with platelet aggregation?

Answer 8

by reversibly or irreversibly inhibiting various steps in the platelet activation required for primary haemostasis

Question 9

name two conditions which can predispose patients to the risk of thrombosis

Answer 9

atherosclerosis
cardiac arrhythmias

Question 10

define thrombosis

Answer 10

when a blood clot (thrombus) blocks a blood vessel, either at the site of formation or after travelling to another critical site (thromboembolism)

Question 11

name 3 consequences of thrombosis

Answer 11

heart attack
pulmonary embolism
stroke

Question 12

name 4 conditions/reasons why a patient might be on anticoagulation or anti-platelet medication

Answer 12

thromboembolic conditions
cardiac conditions
a history of stroke
following surgical procedures such as heart valve replacements, cardiac stents and joint replacements

Question 13

what is the primary consideration in the management of dental patients who are taking anticoagulants or anti platelet drugs and require dental treatment?

Answer 13

the balance of the risks between the reduction in risk of thromboembolic events and increased risk of bleeding

Question 14

what is warfarin used for?

Answer 14

the treatment and prophylaxis of thromboembolism

Question 15

how does warfarin work?

Answer 15

by inhibiting the vitamin k-dependent modification of prothrombin and other coagulation factors, which is required for their normal function

Question 16

name 3 limitations of warfarin

Answer 16

1. narrow therapeutic range
2. sensitivity to diet and drug interactions
3. requirement for frequent monitoring and dose adjustment

Question 17

why do DOACs not require the same degree of monitoring as warfarin?

Answer 17

they produce a more predictable level of anticoagulation

Question 18

what is the mechanism of dabigatran?

Answer 18

A direct inhibitor of the coagulation factor thrombin

Question 19

what is the mechanism of apixaban?

Answer 19

Inhibits factor Xa of the coagulation cascade

Question 20

what is the mechanism of rivaroxaban?

Answer 20

Inhibits factor Xa of the coagulation cascade

Question 21

what is the mechanism of edoxaban?

Answer 21

Inhibits factor Xa of the coagulation cascade

Question 22

what drug should be used for the reversal of dabigatran in patients with life-threatening or uncontrolled bleeding?

Answer 22

idarucizumab (praxbind)

Question 23

what drug should be used for the reversal of apixaban or rivaroxaban in patients with life-threatening or uncontrolled bleeding?

Answer 23

andexanet alfa

Question 24

name 5 parental anticoagulants

Answer 24

1. unfractional heparin
2. low molecular weight heparins (LMWHs)
3. dalteparin
4. enoxaparin
5. tinzaparin

Question 25

how are parental anticoagulants administered?

Answer 25

intravenously or by subcutaneous injection

Question 26

what are the 2 most widely used anti platelet drugs?

Answer 26

aspirin and clopidogrel

Question 27

name 2 relatively new alternatives to clopidogrel

Answer 27

prasugrel (Efient) ticagrelor (Brilique)

Question 28

what are the advantages of prasugrel and ticagrelor over clopidogrel?

Answer 28

- more rapid onset time - more predictable absorption - improved efficacy for some outcomes

Question 29

what is the current guidance for prescribing prasugrel and ticagrelor?

Answer 29

- limited to pts with acute coronary syndrome and coronary stents - usually prescribed in combination with aspirin as dual therapy

Question 30

name 7 dental procedures UNLIKELY to cause bleeding

Answer 30

- LA -BPE - supragingival PMPR - restoration with supra gingival margins - Endodontic treatment - impressions and other prosthetics procedures - fitting/adjustment of orthodontic appliances

Question 31

name 5 dental procedures with LOW RISK of post op bleeding complications

Answer 31

- simple extraction (1-3 teeth) - incision & drainage of intra-oral swellings - 6 point pocket chart - root surface debridement - restoration with sub gingival margins

Question 32

name 4 dental procedures with HIGHER RISK of post op bleeding complications

Answer 32

- complex extractions - flap raising procedures - gingival recontouring - biopsies

Question 33

name 6 flap raising procedures

Answer 33

- elective surgical extractions - periodontal surgery - preprosthetic surgery -periradicular surgery - crown lengthening - dental implant surgery

Question 34

how do you manage patients on anticoagulation/anti-platelet medication for procedures that are unlikely to cause bleeding?

Answer 34

treat according to standard practice, with care taken tp avoid causing bleeding

Question 35

what is meant by "bleeding complications"?

Answer 35

prolonged bleeding or excessive bleeding or bleeding not controlled by initial haemostatic measures

Question 36

how is chronic renal failure associated with an increased bleeding risk?

Answer 36

associated platelet dysfunction

Question 37

how is liver disease associated with increased bleeding risk?

Answer 37

-reduced coagulation factors - reduction in platelet number and function due to splenomegaly - alcohol excess can result in direct bone marrow toxicity and reduced platelet numbers

Question 38

how is haematological malignancy associated with increased bleeding risk?

Answer 38

impaired coagulation or platelet function, even in remission