Anticoagulation therapeutics

Question 1

Time frame for clotting

Answer 1

haemostats seconds - hours
Inflammation hours - days
Proliferation days - weeks
Remodelling weeks - months

Question 2

How does platelet adhesion occur?

Answer 2

Damage to vessel wall exposes collagen and chemical factors

Platelets adhere using vWF

Platelets are activated and release factors into surrounding area = vasoconstriction and subsequent platelet activation

Prostacyclin inhibits platelet adhesion and aggregation

NO inhibits platelet adhesion

Question 3

What does ADP do?

Answer 3

Sticky platelets

Question 4

What does serotonin do?

Answer 4

Vasoconstrictiom

Question 5

What does thromboxane a2 do?

Answer 5

Vasoconstricts and activates

Question 6

Fibrinolytics

Answer 6

TPA, streptokinase and urokinase - break down blood clots

Question 7

Anti-fibrinolytics

Answer 7

Inhibit clot lysis and stabilise clot formation - amicarm, fibrinogen, aprotinin

Question 8

Anticoagulants

Answer 8

Block clotting cascade to prevent blood from clotting - apixaban, dabigatran, rivaroxaban, warfarin

Question 9

function of prostacyclin C

Answer 9

Produced by endothelial wall to prevent platelets adhering

Question 10

How to quantify clotting capability

Answer 10

• Measure platelets
• Calculate INR
• Measure PTT - extrinsic pathway
• Measure APTR - activated partial thromboplastin time - intrinsic

Question 11

Anti-coagulants

Answer 11

• Warfarin
• DOACs - rivaroxaban, dabigatran, apixaban, endoxaban
• Heparin - acts on 10a and thrombin to prevent coagulation

Question 12

Heparin indications

Answer 12

DVT
PE
MI
VTE prophylaxis
Open heart surgery

Question 13

Heparin contraindications

Answer 13

Haemorrhage
Thrombocytopenia
HTN
Lumbar puncture
Surgery
Trauma

Question 14

Heparin complications

Answer 14

Heparin induced thrombocytopenia
Hyperkalaemia
Hypersensitivity

Question 15

Warfarin indications

Answer 15

DVT,
PE
AF
Heart valve prosthetics

Question 16

Warfarin contraindications

Answer 16

Pregnancy
Stroke
Renal/hepatic disease
GI bleed]
Hypertension 
Surgery

Question 17

Complications of warfarin

Answer 17

Increased bleeding risk
Teratogenic - disordered bone development
Skin necrosis

Question 18

How does warfarin affect vitamin K?

Answer 18

Prevents vitamin K reductase so there is no reduced vit K = no modification = affects factors 2,7,9,10

Question 19

What do DOACs inhibit?

Answer 19

Factor 10a/thrombin

Question 20

Indications for DOAC use

Answer 20

Same as warfarin but not for mechanical heart valve

Question 21

Contraindications for DOACs

Answer 21

Acute bleeding
Renal insufficiency
Breastfeeding
Hypertension

Question 22

Complications of DOACs

Answer 22

Dabigatran = GI disturbance 
Rivaroxaban = constipation

Question 23

Indications for fibrinolysis

Answer 23

Acute ischemic stroke
PE
MI

Question 24

Contraindications for fibrinolysis

Answer 24

Aneurysm
GI ulcer
Surgery 
Hypertension 
Endocarditis

Question 25

Complications of fibrinolysis

Answer 25

Anaphylaxis
Cardiac arrest
Haemorrhage
Hypotension

Question 26

Antifibrinolytics example

Answer 26

tranexamic acid

Question 27

Indications for antifibrinolytic use

Answer 27

Menorrhagia
EPistaxis
Prevention and treatment of haemorrhage

Question 28

Contraindications of tranexamic acid

Answer 28

Convulsions

Haematuria