Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

ASDOH Hematology > Episode 6 > Flashcards

Episode 6 Flashcards

1
Q

Substances that prevent the synthesis of a fibrin network which inhibits coagulation and the formation of thrombi

A

Anticoagulants

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

Substances that promote the destruction of already formed blood clots or thrombi ( i.e. – lyse thrombi) by disrupting the fibrin mesh

A

Thrombolytics/Fibrinolytics

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

Drugs that reduce the adhesion and aggregation of platelets

A

Antiplatelets

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

Drugs that promote the formation of clots and prevent excessive bleeding

A

Antifibrinolytics

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

Anticoagulants are generally divided into

A
  • Indirect thrombin inhibitors (HEPARIN)
  • Coumarin Anticoagulants (basically WARFARIN)
  • Direct Thrombin Inhibitors
  • Direct Active Factor X (Xa) Inhibitors
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

three most common preparations or Heparin are

A
  • Unfractionated heparin (UFH) – Heparin Sodium
  • Low-molecular-weight heparin (LMWH)
  • Fondaparinux
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Heparin: How Does It Work?

A

stimulates antithrombin- III, which in turn, neutralizes the activity of factor X

Without factor Xa, prothrombin cannot be converted into thrombin

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

Unfractionated Heparin can have a varied response per individual. The dose and response can be tricky we need to monitor with…

A

aPTT

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

UFH treats

A

Acute thromboembolic disorders (e.g. pulmonary embolism, dear vein thrombosis, disseminated intravascular coagulation)

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

UFH prophylaxis when?

A

Prevent clotting in surgery
Blood transfusions
Renal Dialysis
Blood sample collection

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

Normal APTT is approximately_____, and Therapeutic levels of UFH will prolong that ______ times of normal value.

A

25-36s

2-2.5

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

UFH adverse effects?

A

Spontaneous bleeding

HIT = heparin-induced thrombocytopenia (Type 1 25%, Type 2 5%)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Reversal of UFH Action by…

A

PROTAMINE SULFATE

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

Unfractionated Heparin (UFH) Limitations

A

Binds to a variety of cells and plasma proteins, leading
to unpredictable effects

Difficult to predict dose

aPTT monitoring required

Short half-life (approx. 90 min

Increased risk of heparin-induced thrombocytopenia
(HIT)

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

How are Low Molecular Weight Heparins (LMWHs) Different than UFH?

A

inactivation of factor X than inactivation of thrombin

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

T or F LMWHs need APTT testing.

A

F they don’t need APTT testing

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

Why els are LMWHs better more ideal than UFH

A

Longer duration of action
Fewer cases of HIT
Do not cross Placental barrier

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

Prevent ischemic complications of unstable angina or NSTEMI

A

Low Molecular Weight Heparins (LMWHs)

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

A synthetic low molecular weight heparin (LMWH)

A

Fondaparinux (Arixtra)

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

The only major coumarin anticoagulant in the USA

A

warfarin (Coumadin)

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

Warfarin Pharmacokinetics

A

oral 100% bioavailable
Liver metabolizes
Onset slower than Heparin (8-12hr) may take 3-5 days.
Effects wear off slow 3-5 days.

22
Q

Monitoring Warfarin Therapy is…

A

international normalized ratio (INR)

Dose adjusted to INR of 2.0-3.0.

23
Q

Warfarin should never be used in

A

pregnancy (category X under the old FDA pregnancy categories)
Fetal warfarin syndrome

24
Q

Warfarin has many drug interactions that may disrupt its effects by inhibiting its metabolism, most common are…

A

Many antimicrobials
Cimetidine (Tagamet)
Acetaminophen (Tylenol)

25
Q

Warfarin has many drug interactions that may enhance its effects most common are…

A 
Synthetic thyroid hormones
cephalosporins
Tetracyclines
SSRIs
Herbs
Corticosteroids
26
Q

Warfarin has many drug interactions that may enhance its effects by stimulating its metabolism, most common are…

A
  • Griseofulvin
  • Rifampin
  • Anti-thyroid agents (methimazole, PTU)
27
Q

Directly antagonizes the effect of warfarin on clotting factor synthesis and is used to treat severe hemorrhage caused by warfarin overdose (in addition to withholding warfarin or decreasing its dose)

A

Phytonadione (vitamin K1)

28
Q

LOTS of patients are being switched from warfarin to…

A

dabigatran

29
Q

Antidote for patients treated with dabigatran

A

idarucizumab (Praxbind)

30
Q

Dabigatran is Contraindicated in patients with active pathological bleeding or…

A

a mechanical prosthetic heart valve

31
Q

Direct Active Factor X (Xa) Inhibitors

A

Rivaroxaban (Xarelto) First one
Apixaban (Eliquis)
Edoxaban (Savaysa)

All are administered orally and do not require frequent blood tests for INR

32
Q

The main classes of antiplatelet agents are:

A
  • Cyclooxygenase Inhibitors (mainly aspirin)
  • Thienopyridines (ADP Inhibitors)
  • GP IIb/IIIa Inhibitors
33
Q

Aspirin acts on platelets by

A

inhibiting the synthesis of TXA2

34
Q

These drugs act by preventing the binding of ADP to its receptors (ADP-P2Y12 receptors) on platelets, thereby inhibiting an important pathway that leads to platelet aggregation.

A

ADP Inhibitors

35
Q

ADP Inhibitors Examples

A
  • Clopidogrel (Plavix)
  • Prasugrel (Effient)
  • Ticagrelor (Brilinta)
  • Ticlopidine
36
Q

The blockage of ADP-P2Y12 receptors on platelets does 2 things:

A

• Reduces the attraction of platelets to the scene of injury
• Inhibits the expression of GP IIb/IIIa
receptors

37
Q

Contraindications Ticlopidine only

A

severe neutropenia that must be monitored via CBC

38
Q

Contraindications Clopidogrel

A

action can be enhanced by CYP2C19 inhibitors (most notably PPIs)

39
Q

Contraindications Ticagrelor

A

avoid taking with CYP3A4 inhibitors or inducers

40
Q

GP IIb/IIIa Inhibitors Examples include:

A
  • Abciximab (ReoPro) – irreversible inhibitor
  • Tirofiban (Aggrastat) – reversible inhibitor
  • Eptifibatide (Integrilin) – reversible inhibitor
41
Q

GP IIb/IIIa Inhibitors These agents are administered..,

A

IV, typically with an initial bolus (loading dose) followed by constant (maintenance) infusion

42
Q

derived from southeastern pygmy rattlesnake (Sistrurus miliarius barbouri; found in SE US)

A

Eptifibatide

43
Q

Thrombolytics / Fibrinolytics Examples include:

A 
• Streptokinase (from streptococci)
• Urokinase (from neonatal kidney cells) 
• Synthetic (recombinant) tPA 
alteplase (Activase), reteplase
(Retavase), tenecteplase (TNKase)
44
Q

is “clot-specific” – in other words, it has a low affinity for free plasminogen, as it only activates plasminogen associated with fibrin

A

Recombinant tPA

45
Q

are drugs that promote the formation of clots and/or prevent excessive bleeding

A

anti-fibrinolytics

46
Q

Antifibrinolytic prevents plasmin from binding to fibrin

A

tranexamic acid

47
Q

is used in dentistry in the form of a 5% mouth rinse after extractions or surgery in patients with prolonged bleeding time

A

tranexamic acid

48
Q

Antifibrinolytic which prevents plasminogen activation to plasmin

A

aminocaproic acid

49
Q

What is Warfarin’s mechanism of action?

A

inhibits the vitamin K-dependent synthesis of biologically active forms of the calcium-dependent clotting factors II, VII, IX and X, as well as the regulatory factors protein C, protein S

50
Q

Direct Thrombin Inhibitors

A

Desirudin
Bivalirudin
Hirudin

ASDOH Hematology (6 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions