Brainscape's Knowledge GenomeTM

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


See full index

Pharmacology > Anti-clotting drugs > Flashcards

Anti-clotting drugs Flashcards

0
Q

Warfarin pharmacokinetics

A

Good GI absorption, can be given PO
Slow onset-give heparin cover for the first few days
Slow offset (T1/2 ~48 hrs)
Crosses placenta-teratogenic in first trimester, brain haemorrhage in 3rd trimester
Heavily protein bound
CYP450 metabolism

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

Warfarin mechanism

A

Prevents reduction of vitamin K
Inhibits production of vitamin K dependent clotting factors (7,9,10,2)
Gla residues can’t form so no localisation of clotting factors.

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

Warfarin monitoring

A

Prothrombin time

INR

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

Warfarin uses

A

AF
Thromboses associated with inherited conditions
DVT (3-6 months)
Mechanical prosthetic valves

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

Warfarin ADRs

A

Teratogenic
Haemorrhage
Give anticoagulant card

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

Warfarin DDIs

A

Aspirin
CYP450 inhibitors
Cephalosporins (inhibit vitamin k production by colonic bacteria)
All potentiating

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

Heparins mechanism

A

Glycosaminoglycan produced by mast cells
Activate anti thrombin 3
Deactivates factors 10a, 2a, 9a, possibly also 8a, 11a, 12a)

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

Warfarin reversal

A

Vitamin k

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

Unfractionated heparin

A

Chains of 12-15 kd
Loading dose, then IV
Monitor APTT
Is large enough to bind factor 2a (unlike LMWH)

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

Low molecular weight heparins

A 
Smaller chains -4-5 kd 
Long T1/2
Subcutaneous 
Higher bioavailability (~90%)
More predicable dose response - usually no monitoring required
Cleared by kidneys
Less risk of thrombocytopenia
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Heparin reversal

A

Stop heparin

Protamine sulphate - dissociates heparin from AT3 - if actively bleeding

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

Heparin uses

A 
Immobility
Perioperative (low dose LMWH)
DVT/PE/AF
Acute coronary syndromes
Warfarin cover -operations, pregnancy
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Heparin ADRs

A

Bruising/bleeding-GI, intracranial, epistaxis, injection sites
Osteoporosis
Thrombocytopenia - can be autoimmune as platelets activated and used up. (PF4 receptor)

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

Clopidogrel

Prascigrel

A

ADP antagonists
Inhibit ADP dependent platelet aggregation
Indicated in ACS or PCI
Can be given with aspirin - bleeds more serious but not more life threatening.
Not long term

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

Dipyridamole

A

Probably a phosphodiesterase inhibitor
Positive isotrope, vasodilatory
Secondary prevention of stroke

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

Glycoprotein 2b/3a receptor antagonists

A

Fibrinogen usually binds here, resulting in platelet aggregation
Used in high risk ACS and post PCI-increased bleeding risk but reduced thrombosis and re stenosis.

16
Q

Streptokinase mechanism

A

Converts plasminogen to plasmin

Thrombolysis occurs when plasmin >alpha 2 anti plasmin

17
Q

Streptokinase pharmacokinetics

A

T1/2 ~ 15 mins
Streptokinase/plasminogen complex T1/2 ~3 mins
IV infusion
Cleared by liver

18
Q

Streptokinase ADRs

A

Hypotension

19
Q

Fibrinolytic reversal

A

Tranexamic acid

Inhibits plasminogen binding

20
Q

Recombinant TPA advantages

A

Non immumogenic

Fibrin specific - less systemic disturbance

21
Q

Recombinant TPA pharmacokinetics

A

Reteplase + tenecteplase T1/2 ~14-17 mins
Renal and hepatic clearance
Alteplase T1/2 ~ 3 mins
Hepatic clearance

22
Q

Recombinant TPA issues

A

May stimulate thrombin and platelet activation

Give heparin alongside

23
Q

Alteplase

A

Recombinant TPA

24
Q

Reteplase

A

Recombinant TPA

25
Q

Tenecteplase

A

Recombinant TPA

26
Q

Contraindications to thrombolysis

A 
History of haemorrhagic stroke
Peptic ulcer or other potential bleeding source 
Recent trauma or surgery 
CNS neoplasm
Aortic dissection 
Uncontrolled hypertension
Known bleeding disorder
27
Q

Indications for thrombolysis

A

MI in last 12 hours

Stroke in last 3 hours (up to 4.5)

28
Q

Bivalrubin

Desirubin

A

Direct thrombin inhibitors

29
Q

Fondaparinux

Idaparinux

A

Specific factor Xa inhibitors

Pharmacology (20 decks)

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