Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Pharm 2 > Anticoagulants > Flashcards

Anticoagulants Flashcards

(63 cards)

Start Studying
1
Q

Do anticoagulants have a high or low Vd?

A

low because you want it to stay in the blood

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is hemostasis?

A

the cessation (ending) of blood loss from a damaged vessel

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is hemostasis for?

A

-prevent blood loss
-prevent thrombosis (clot blocks vein or artery)
-aid in clot removal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what are the similarities between antiplatelet and anticoagulant drugs?

A

-they are both present in hemostasis
-they both are used in stroke prophylaxis and acute coronary syndromes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What are some differences between antiplatelet and anticoagulant drugs?

A

-antiplatelets only work on platelets = weaker = safer
-antiplatelets can be used for stroke treatment, not anticoagulants
-anticoagulants can be used for heart valve replacement = triggers immune response = clotting

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What are the three componenets of hemostasis?

A

-blood vessels
-platelets
-coagulation factors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What are the steps of primary hemostasis?

A

goal: aggregation

vasoconstriction -> platelet aggregation -> clotting -> go to area to be clotted -> combine with fibrin to cement mesh and create clot

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

what are the steps of secondary hemostasis?

A

goal: coagulation

thrombin -> fibrin -> combine with aggregated platelets to form clot

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Does primary and secondary hemostasis occur simultaneously or sequentially?

A

simultaneously

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

How is a platelet plug formed?

A

damaged vessel or capillary -> immediate reflex -> vasoconstriction -> exposed collagen promotes platelet adherence -> degranulation and release cytoplasmic granules -> contain serotonin (vasoconstrictor), ADP and thromboxane A2 -> ADP attracts platelets -> thromboxane promote aggregation, degranulation and vasoconstriction -> positive feedback loop and platelet plug is formed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What are the three basic mechanisms that promote hemostasis?

A
  1. immediate vasoconstriction
  2. exposed collagen promote platelet adherence = degranulate and release granules with serotonin, ADP and Thromboxane
  3. serotonin, ADP and thromboxane promote more platelet adhesion and aggregation and vasoconstriction
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What are the steps in coagulation?

A
  1. damaged tissue -> release factor 3 -> activate factor 7 with Ca (extrinsic)
  2. active platelets -> release factor 12 -> activates factor 11 (intrinsic)
  3. factor 7 and 11 activate reactions that activate factor 10
  4. factor 10, 3, 5, Ca, and PF3 (platelet thromboplastic factor) -> activate prothrombin activator -> converts prothrombin to thrombin -> converts fibrinogen to fibrin
  5. fibrin loose mesh + factor 12 -> covalent crosslinks -> dense fiber aggregation -> catches RBC and platelets -> blood clot
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What does thrombin do?

A

changes fibrinogen to fibrin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What are the characteristics of a resting platelet?

A

-round shape
-inactive GP 2b/3a receptors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

what does prostacyclin do

A

vasodilation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what are the characteristics of an activated platelet?

A

-oblong shape
-activated GP 2b/3a receptors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

what does cAMP do?

A

inhibits the release of calcium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What do GP 2b/3a receptors do?

A

-important to blood clot formation
-signaling and binding to fibrinogen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What activates GP 2b/3a receptors?

A

release of calcium in the platelet

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What three things activate calcium release within platelets?

A

-thrombin
-thromboxane A2
-ADP

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What are two clotting factor diseases and what causes them?

A

-hemophilia: recessive X-linked genetic disorder; no functional factor 8 and 9
-Von Willebrand disease: genetic lack of vWF

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What are some characteristics of platelets?

A

-no nucleus
-contain remnants of ER (have Ca2+)
-produced from megakaryocytes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What are the three steps of the platelet response?

A

-adhesion
-activation
-aggregation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What are the three receptors responsible for platelet adhesion and what are their functions?

A
  1. GP1a = binds to exposed collagen
  2. GP2b/3a = promotes aggregation
  3. GP1b = binds to vWF
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
What is vWF?
-a blood glycoprotein -promotes hemostasis and platelet adhesion
26
What are three things that activate COX-1 in platelet activation?
-arachidonic acid -collagen -thrombin
27
What component is the most important to activate the platelets?
overdose of calcium
28
What does COX-1 activate in platelet activation?
thromboxane A2 which activates GP 2b/3a which promotes aggregation
29
What three things act on platelets to promote aggregation?
-ADP -Thrombin -TxA2
30
What are the two pathways for coagulation and what are its key players?
-intrinsic pathway: factor 11 -extrinsic pathway: factor 7
31
What parts of the coagulation cascade require calcium
-both intrinsic and extrinsic -some of the last steps too
32
What is the order of mediators and factors in the intrinsic pathway?
charged surface -> 12a -> 11a -> 9a -> 10a -> thrombin (2a) -> thrombin-fibrin clot
33
What is the order of mediators and factors in the extrinsic pathway?
-tissue damage -> tissue factor (3) -> 7a -> 10a -> thrombin -> thrombin-fibrin clot
34
What factors act on factor 10a?
-factor 7, 9, 8,11
35
**List the indirect thrombin inhibitors
-unfractionated heparin -Low molecular weight heparin -rivaroxiban -fondaparinux
36
Why is unfractionated heparin only given IV or SC?
-because IM can lead to hematoma = blood in the muscle
37
What is another name for thrombin?
-factor 2a
38
What part exactly binds to antithrombin 3?
pentasaccharide sequence in the polysaccharide chain of the thrombin inhibitor drug
39
How is heparin removed from the body?
-cleared by macrophage/monocyte system -inactive metabolites and left over parent drug excreted into urine
40
What are some differences between UFH and LMWH?
-LMWH can be given SC -LMWH has better bioavailability (90% vs 30%) -LMWH has less bleeding = safer = less monitoring -LMWH has longer half life (4-6h) -UFH only has t1/2 of 0.5-1h
41
Why does LMWH have a better bioavailability than UFH?
because it has short chains so it is easier to go to the blood and less is lost in transport
42
What are the three main complications of heparin therapy and how are they treated?
-bleeding -> protamine sulfate -osteoporosis -> 3-6mo treatment -heparin-induced thrombocytopaenia (HIT) -> depends
43
What are the types of HIT and how are they different?
-HIT 1: 10% of pt; non-immune; benign -HIT 2: 0.5-1% of pt; immune related; can lead to venous or arterial thrombosis
44
high risk HIT: how it occurs?
platelets contain PF4 -> when injured platelets release PF4 -> if heparin is present, body makes heparin antibodies -> heparin binds to heparin IgG -> binds to PF4 -> increases platelet activation -> platelet to fibrin/thrombin ration off -> excessive coagulation -> collapses veins -> may lead to dead tissue
45
What is the difference between indirect and direct thrombin inhibitors?
-indirect: requires antithrombin; no effect on thrombin in clots because antithrombin cannot reach the thrombin -direct: can bind to thrombin in clots; displaces from clots
46
What does thrombin do in the presence of an indirect inhibitor if it is trapped in a clot?
-indirect inhibitors do not displace the thrombin from the clot, so the thrombin will continue to make fibrin and activate platelets
47
Where is a lot of Vitamin K stored in the body?
the liver
48
What factors require vitamin K for their creation?
factor 2, 7, 9, 10
49
What are the issues with warfarin?
1. its abs is decreased in the presence of cholestyramine 2. pt has hypoproteinemia (low protein) = no protein to bind to warfarin = increases Vd and shortens half life 3. antibiotics decrease K+ because remove gut flora = excessive effects of warfarin 4. eating vit K rich foods = work against warfarin 5. other drugs that inhibit or increase the metabolic effects of CYP2C9 will affect warfarin effects
50
Where in the body does warfarin work?
the liver
51
What is warfarin-induced skin necrosis caused by?
-due to inhibition of protein C = results in clotting
52
What is the target of warfarin?
Vitamin K enzyme
53
What is the target of dabigatran?
thrombin
54
What interacts with dabigatran?
P-glycoprotein
55
What is the target of rivaroxaban?
Factor 10a
56
What interacts with rivaoxaban?
-CYP3A4 -P-glycoprotein
57
What is the target of apixaban?
-factor 10a
58
What interacts with apixaban?
-CYP3A4 -P-glycoprotein
59
What are three laboratory tests done to monitor the affects of anticoagulants?
-Partial Thromboplastin Time (aPTT) -Prothrombin Time (PT) -International Normalized Ratio (INR)
60
What is the standard for blood clotting?
-blood clots in 4-8 min in test tube -recalcified plasma clots in 2-4min
61
How does Partial Thromboplastin time work?
-measures intrinsic pathway -normal pt: if you add phospholipids to recalcified blood -> clotting in 26-33 seconds -if clotting time doesn't shorten -> intrinsic pathway not working -if clotting takes shorter time -> excessive amount of factors
62
How does Prothrombin Time work?
-measures extrinsic pathway -normal pt: add phospholipids and thromboplastin to recalcified blood -> clots in 12-14 sec -if clotting takes longer = extrinsic not working -if clotting is immediate = excess factors/overactive
63
How does INR work?
-prothrombin ratio -goal: INR 2-3 -INR = patients PT (s)/mean normal PT (s) -ISI = relative sensitivity of PT compared to WHO standard

Pharm 2 (11 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions