Bleeding Disorder Drug Flashcards
In secondary coagulation the extrinsic pathway is started when damaged endothelial cells release factor III (tissue factor III) which binds with the active factor VIIa (7a) and Ca2+. This then forms the VIIa-TF complex on the smooth muscle of blood vessels. The VIIa-TF complex then cleaves what factor?
1 - factor II (2 or prothrombin)
2 - factor X forming Xa
3 - factor VIII (8)
4 - factor V (5)
2 - factor X forming Xa
Once factor Xa has become active due to the extrinsic pathway, what factor does Xa (10a) and Ca2+ bind with that will then go onto form the prothrombinase complex?
1 - factor II (2 or prothrombin)
2 - factor I (1)
3 - factor VIII (8)
4 - factor V (5)
4 - factor V (5)
Once the prothrombinase complex has been formed by active factors X (10) and V (5), what does this then cleave in the extrinsic pathway?
1 - factor II (2 or prothrombin)
2 - factor I (1)
3 - factor VIII (8)
4 - factor XII (12)
1 - factor II (2 or prothrombin)
- prothrombin becomes thrombin (IIa)
Which pathway of the coagulation cascade doe the prothrombin time (PT), which is essentially the time it takes to form a clot measures?
1 - common
2 - extrinsic
3 - intrinsic
2 - extrinsic pathway
- essentially this is the time it takes to form a clot
- tissue factor (III), Ca2+ and factor VII (7) form complex and active factor X (10)
- factor X (10) binds factor V (5) and Ca2+ and cleaves prothrombin into thrombin, which is where the name prothrombin time comes from
What is the normal value for prothrombin time (PT), which is essentially the time it takes to form a clot?
1 - 0.1 - 1.4 secs
2 - 1-4 secs
3 - 10-14 secs
4 - 15-20 secs
3 - 10-14 secs
In the coagulation cascade, activated partial thromboplastin time (aPTT) is a measure of which aspect of the coagulation cascade?
1 - common
2 - extrinsic
3 - intrinsic
3 - intrinsic
- time it takes the intrinsic and common pathway to form a clot following the addition of calcium and phospholipid emulsion in-vitro
In the coagulation cascade, activated partial thromboplastin time (aPTT) is a measure of the intrinsic and common pathway to form a clot following the addition of calcium and phospholipid emulsion. What is the normal time for this?
1 - 0.1 - 1.4 secs
2 - 1-4 secs
3 - 10-14 secs
4 - 27-41 secs
4 - 27-41 secs
What is the international normalised ratio (INR)?
1 - measure of aPTT compared to age and gender matched aPTT
2 - measure of AP
3 - measure of PT as a ratio to a standardised or control PT
3 - measure of PT as a ratio to a standardised or control PT
- PT is a measure of how long it takes clot to form
- measures extrinsic pathway
The international normalised ratio (INR) is a measure of PT as a ratio to a standardised or control PT. What is a normal value for INR?
1 - 0.1 - 1.4
2 - 1-1.3
3 - 10-14
4 - 27-41
2 - 1-1.3
What is the purpose of the coagulation cascade?
1 - accentuate primary haemostasis
2 - convert fibrinogen into fibrin
3 - inhibit platelets activation in primary haemostasis
2 - convert fibrinogen into fibrin
- fibrinogen = factor 1
- fibrin = 1a
- fibrin are monomers that form crosslinks and a strong clot
The coagulation cascade has 3 parts, intrinsic, extrinsic and common pathways. How is the intrinsic pathway started?
1 - factor XII (12) comes into contacts with collagen or activated platelets
2 - factor X (10) binds with fibrin
3 - factor XII (12) binds von willebrand factor
4 - factor XII (12) binds inactive platelets
1 - factor XII (12) comes into contacts with collagen or activated platelets
- platelets are activated from primary haemostasis
Once the intrinsic pathway has begun by factor XII (12) binding with activated platelets or collagen, what then happens in the intrinsic pathway?
1 - factor XII (12) then becomes factor X (10)
2 - activated platelets activate factor XI
3 - factor XII (12) becomes factor XIIa (12a) and activates factor XI (11), then IX (9) and then X (10)
4 - collagen activates factor XI (11)
3 - factor XII (12) becomes factor XIIa (12a) and activates factor XI (11), then IX (9) and then X (10)
In the intrinsic pathway, which factor activates the common pathway?
1 - factor XIIa (12a)
2 - factor XIa (11a)
3 - factor IX (9)
4 - factor Xa (10a)
4 - factor Xa (10a)
- Xa (10a) then activates factor II (2) called thrombin
- factor II (2) called thrombin then activates factor I (1) which builds the fibrin mesh
Once the common pathway has been activates by factor Xa (10) it activates factor II (2 thrombin) which activates factor Ia (1a, called fibrin) which begins building fibrin. Which 4 other cofactors is factor IIa (2a thrombin) able to also activate?
1 - Ia (1a), IIIa (3a), IVa (4a) and V (5a)
2 - XIa (11a), IIIa (3a), IVa (4a) and VIIa (7a)
3 - IIIa (3a), IVa (4a), Va (5a) and XIIa (12a)
4 - Va (5a), VIIIa (8a), IXa (9a) and XIIIa (13a)
4 - Va (5a), VIIIa (8a), IXa (9a) and XIIIa (13a)
- Va (5a) acts as a cofactor for factor Xa (10a)
- VIIIa (8a) acts as a cofactor for factor IXa (9a)
- IXa (9a)
- XIIIa (13a) helps factor I (1a) called fibrin form crosslinks and a stronger clot
The extrinsic pathway is activated when factor VIIa (7a) binds with what on exposed tissue?
1 - von Willebrand factor
2 - tissue factor
3 - tissue plasminogen factor
4 - protein C
2 - tissue factor
- factor VIIa (7a) then activates the factor Xa (10a) and the common pathway
In secondary haemostasis, which factor is often referred to as the accelerator due to its multiple procoagulating functions?
1 - factor IIa (2a)
2 - factor Xa (10a)
3 - factor Va (5a)
4 - factor Ia (1a)
1 - factor IIa (2a)
- also referred to as thrombin
Thrombin (factor IIa (2a) is able to do lots of things involved in coagulation. It does all of the following EXCEpt which one?
1 - binds platelets activating them
2 - activates factor Va (5a)
3 - activates factor VIIIa (8a)
4 - converts fibrinogen (factor I (1) into fibrin (factor Ia (1a))
5 -converts factor XIII (13) into factor XIIIa (13a) that binds with Ca2+ cofactor forming cross bridges between fibrin mesh
6 - activates protein C and S
6 - activates protein C and S
- proteins S and C ensure clotting does not go into overdrive
Factor IIa (2a) also called thrombin is one of the key cofactors in secondary haemostasis. What is the bodies natural molecule that aims to modulate the activation of thrombin?
1 - protein S
2 - protein C
3 - antithrombin (factor IIIa (3a))
4 - factor Va (5a)
3 - antithrombin (factor IIIa (3a))
Factor IIa (2a) also called thrombin is one of the key cofactors in secondary haemostasis. Antithrombin (factor IIIa (3a)) is the bodies naturally produced modulator of thrombin. Which 2 key factors in the common pathway is antithrombin (factor IIIa (3a)) able to bind with and reduce coagulation?
1 - factors Va (5a) and Xa (10a)
2 - factors IIa (2a) and Xa (10a)
3 - factors XIIIa (8a) and Xa (10a)
4 - factors IIa (2a) and XIIIa (13a)
2 - factors IIa (2a) and Xa (10a)
- this essentially inhibits or reduces the activity of the common pathway
- factor Xa converts prothrombin into thrombin (factor IIa (2a))
- remember 2 + 7 = 9, 10, 11, 12
Which factors overall is anti-thrombin (IIIa (3a)) able to bind with and inhibit?
1 - factors 1, 2, 3, 4 and 5
2 - factors 2, 7, 9, 10, 11 and 12
3 - factors 1, 2, 7, 9 and 10
4 - factors 5, 7, 9, 11, 13
2 - factors 2, 7, 9, 10, 11 and 12
- remember 2 + 7 = 9, 10, 11, 12
Which factors in the coagulation cascade synthesised in the liver are vitamin K dependent?
1 - 2, 3, 4 and 5
2 - 2, 7, 9 and 10
3 - 2, 4, 6 and 8
4 - 2, 7, 10 and 12
2 - 2, 7, 9 and 10
- all factors are enzymes
- these enzymes require vitamin K to be effective
Which factors of the coagulation cascade is Warfarin able to inhibit?
1 - 2, 3, 4 and 5
2 - 2, 7, 9 and 10
3 - 2, 4, 6 and 8
4 - 2, 7, 10 and 12
2 - 2, 7, 9 and 10
- inhibits vitamin K factors II (2), VII (7), IX 9 and X (10) - coagulation
- 1972 was the year of diSCo
- factors 9, 7, 2 and 10
- proteins S and C
In addition to inhibiting factors 2, 7, 9 and 10, what 2 other proteins is Warfarin able to inhibit?
1 - albumin
2 - protein S
3 - protein C
4 - fibrinogen
2 - protein S
3 - protein C
- 1972 was the year of diSCo
- factors 9, 7, 2 and 10
- proteins S and C
Warfarin is able to inhibit the synthesis of factors 2, 7, 9 and 10 in the coagulation cascade. However, what enzyme is Warfarin able to inhibit to cause an anti-coagulability state?
1 - vitamin K hydroquinone
2 - glutamyl carboxylase
3 - vitamin K epoxide reductase
4 - quinone reductase
3 - vitamin K epoxide reductase
- essentially stops the recycling of vitamin K
Is vitamin K a fat soluble vitamin?
- yes
What of the following are required in the GIT for vitamin K to be digested and absorbed?
1 - gut microbiota
2 - fat
3 - bile
4 - pancreatic lipase
5 - all of the above
5 - all of the above
Once digested and absorbed, typically what are the 2 sites where vitamin K is stored in the body?
1 - liver
2 - pancreas
3 - fat cells
4 - muscle cells
1 - liver
3 - fat cells
What is the typical medical name given to vitamin K when administered to patients?
1 - thiamine
2 - ergocalciferol
3 - phytomenadione
4 - quinone
3 - phytomenadione
In which of the following is phytomenadione (vitamin K) indicated for the use in?
1 - wernickes encephalopathy
2 - megablastic anaemia
3 - spinal cord degeneration
4 - reversal of warfarin or vitamin K deficiency
4 - reversal of warfarin or vitamin K deficiency
- recommended in newborn babies to prevent vitamin K deficiency bleeding
When given via IV, what is the main adverse event of phytomenadione (vitamin K)?
1 - bleeding
2 - hypertension
3 - AKD
4 - anaphylactic shock
4 - anaphylactic shock
Phytomenadione (vitamin K) is given to reverse the effects of warfarin. Which of the following instances would the effect of Phytomenadione (vitamin K) be reduced?
1 - colon disease
2 - renal disease
3 - liver disease
4 - stomach disease
3 - liver disease
- coagulation factors are made in the liver
- even if you get vitamin K via IV, the liver is not working properly so factors produced by the liver would not be present
Once Phytomenadione (vitamin K) has been administered we generally monitor the INR, which is a measure of the extrinsic pathway vs a normal control clotting ratio. How long does it take for the effects of Phytomenadione to take effect?
1 - 1-2 hours
2 - 6-12 hours
3 - 24-48 hours
4 - >72 hours
3 - 24-48 hours
