medically complex - anti coag

Question 1

what test for warfarin and heparin

normal values for INR

Answer 1

warfarin: PT and INR (2-3 safe for exo, normal ppl 1)

heparin: aPTT

PT: prothrombin time
aPTT: activated partial thromboplastin time

Question 2

define PT and the normal value

Answer 2

prothrombin time, time taken for clot formation

tests the extrinsic and common pathway

normal 10-12s

Question 3

define aPTT

Answer 3

activated partial thromboplastin time

for unfractionated heparin monitoring

Question 4

what are antiplatelet drugs

Answer 4

• aspirin
• clopidogrel

Question 5

common indications for aspirin

Answer 5

• stroke
• reduce risk of recurrent MI

Question 6

adverse effects of aspirin

Answer 6

• GI bleeding
• reyes syndrome in kids

Question 7

what are anticoagulant drugs

Answer 7

• heparin
• warfarin

Question 8

Functions of aspirin

Answer 8

• NSAID
• weak antipyretic
• anti inflammatory
• anti platelet

Question 9

MOA of warfarin

Answer 9

• vitK antagonist
• vit K is required for formation of factors II, VII, IX, X –> responsible for extrinsic & common pathway

Question 9

what kind of patients will be on Dual antiplatelet therapy?

Answer 9

• recent MI
• coronary stent

Question 10

adverse effects of heparin and what drug to reverse it

Answer 10

haemorrhage

reverse effects with protamin sulfate

Question 10

what kind of pt will be on heparin

Answer 10

• hemodialysis patients

Question 11

what kind of pt will be on warfarin

Answer 11

• mechanical heart valve
• afib patients

Question 12

how to reverse effects of warfarin

Answer 12

vit K
prothrombin complex concentrate

Question 13

HOW LONG does INR take to normalise after stopping warfarin

Answer 13

5 days

Question 14

what drugs to avoid for warfarin patients? DDI

these drugs potentiate the effects of warfarin, increase bleeding risk

Answer 14

• Azole antifungals: Miconazole (commonly given in dentistry)
• NSAIDs: aspirin, ibuprofen, celecoxib
• Most antibiotics
• Paracetamol >2g/day unsafe
• Macrolides: Azithromycin, Clarithromycin

Be careful when giving medications for Warfarin pts

Question 15

what drugs inhibit the effects of warfarin

Answer 15

• cyclosporin
• carbamazepine

Question 16

what drugs can u give patient on warfarin

Answer 16

• paracetamol < 2g/day
• can give penicillin ig but be careful it may potentiate effects of warfarin

Question 17

What are DOAC? direct oral anti coagulants examples

what are they used for?

Answer 17

• Dabigatran (direct thrombin inhibitor)
• Rivaroaxaban, Apixaban (factor Xa 10 inhibitor)

Generally used to replace warfarin as it is safer, more rapid onset and no INR monitoring required

Question 18

what is a safe guideline INR for warfarin patients

Answer 18

2-3
increased INR means clotting time is prolonged

Question 19

what is INR

Answer 19

international normalised ratio

to measure and standardize prothrombin time test

used to monitor patients on warfarin therapy

Question 20

what measures to take for patients on DOAC?

Answer 20

can stop 1 day prior and continue 1 day after op

Question 21

how to manage pt on dual antiplatelet therapy for exo

Answer 21

stop 1 medication. consult medical physician

Question 22

for patients on mechanical heart valve, INR maintained at what value

Answer 22

2.5-3.5

bc very thrombotic, need to further increase the clotting time if not blood clots will form v easily

Question 23

when and how to bridge warfarin with heparin?

Answer 23

- stop warfarin 5 days before surgery - start LMWH 3 days prior to surgery - stop LMWH 24h before surgery - check INR on day of surgery - 1 day post-op: restart LMWH if no major bleeding risk - 2-3 days post op: restart warfarin - 5 days post op: stop LMWH once INR stabilized >2 for 2 consecutive days

Question 24

what to do for patients on warfarin? -pre and post op measures

Answer 24

- consult primary physician - take INR no more than 24h before/ take on day of surgery - treat if INR <3 WITHOUT INTERRUPTING MEDICATION

Question 25

mx for patients on NOAC (rivaroxaban, dabigatran, apixaban) | low & high risk different mx

Answer 25

- avoid surgery at peak of meds: 2-4h post meds - do procedures at least 4h after medications and take local measures - if pt keeps bleeding post op, stop medication for 1 day

Question 26

mx for patients on antiplatelets (aspirin, clopidogrel) | aspirin vs DAPT

Answer 26

For aspirin, no interruptioins for DAPT, ask physician if can stop 1 medication for LA procedures *IF recent MI, no dental procedures within 6m

Question 27

what kind of pts dont touch their AC/ AP therapy?

Answer 27

- prosthetic heart valve - pulmonary embolism/ stroke/ dvt in past 3 months

Question 28

is simple extraction counted low risk? how many teeth then high risk?

Answer 28

1 teeth low risk only coomplex/ > 3 teeth high risk

Question 29

general guidelines for dental procedures for AC/ AP patients?

Answer 29

- do pre-op tests: INR, PT etc - can continue with most procedures without stopping - take local measures: hemostats, suturing

Question 30

what are local measures done for AC/ AP patients?

Answer 30

- atraumatic exo (no raise flap, gutter bone) - remove all granulation tissue - use hemostatic agent: surgicel - sutre and gauze pressure pack - ensure all bleeding stop before sending patient off - give TXA mouthwash; start using next day: 500mg tablet in 10mL water = 5% TXA - give paracetamol for pain relief, avoid NSAIDs

Question 31

what INR values for warfarin is good and bad for exo | for warfarin, INR and PT done on day of surgery

Answer 31

INR < 3: proceed with local measures INR >3: delay procedure, consider heparin bridging - add heparin via IV, slowly wane warfarin - check aPTT and INR until satisfactory - after exo, resume warfarin once hemostasis achieved, wane heparin