Brainscape's Knowledge GenomeTM

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


See full index

Pharm > Anti-coagulants > Flashcards

Anti-coagulants Flashcards

1
Q

Steps of hemostasis

A

1) Local vasoconristion
2) Formation of primary hemostatic plug
3) Formation of thrombus due to coagulation
4) Fibrinolysis- degradation of blood clot

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

Primary hemostasis stepns

A

1) vascular injury (exposes reactive subendothelial proteins)
2) Platelet adhesion and activation
a) Thromboxane A2 (TXA2)synthesized from arachidonic acid by COX-1, potent vasoconstrictor and platelet activator
b) Conformational change in the integrin receptor, resulting in fibrinogen binding
3) platelet granule release
a) ADP activates integrin receptor
b) TXA2
c) Calcium release- important for clotting factors

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

Thrombosis risk factors

A
  • Endothelial injury
  • surgical procedure
  • Hypercoagulability
  • oral contraceptives
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

types of drugs to treat thrombosis

A
  • Antiplatelet drugs (prevents primary plug)
  • Anticoagulant drugs (inhibits fibrin clotting cascade)
  • Thrombolytic drugs( dissolve an existing clot)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Aspirin pharmacology

A
  • Inhibits thromboxane A2 via irreversible acetylation of COX-1
  • rapid absorption
  • Better at lower doses
  • Effect lasts for the lifespan of a platelet (7-10d)
  • nothing more effective
  • Adverse effects: increased hemorrhagic stroke; GI bleeding
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Clopidogrel (pharmacology, adverse effect and therapy)

A
  • Irreversible inhibits P2Y12 ADP receptor
  • ADP receptor blockade inhibits activation of the glycoprotein IIb/IIIa pathway (final common pathway for platelet aggregation
  • Therapeutic uses reduction of rate of stroke, MI, heart attack, unstable angina and death in patients with recent MI, peripheral artery disease, or acute coronary syndrome
  • Equivalent to aspirin in prevention of stroke
  • Adverse effects: prolonged bleeding, thrombotic thrombo cytopenic
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Integrin receptor GP IIb/IIIa inhibitors (pharmacology, adverse effect and therapy)

A

Fab fragment of humanized monoclonal antibody against the GFPIIb receptor long duration (10hrs)

  • therapeutic uses: used with aspirin and heparin to treat coronary thrombosis or during coronary angioplasty, reduces restenosis , recurrent MI
  • Adverse effect: major hemorrhagic event 1% to 10% of patients
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Dental considerations of anti platelet drugs

A

Antiplatelet can cause excessive bleeding

  • Aspirin/clopidogrel when used prophylactically can be discontinued for dental procedure
  • patient with recent stent should not stop or with hold aspirin or clopidogrel
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

HMW Heparin Pharmacology

A
  • catalyzes inhibition of clotting factors IXa, Xa and thomin by enhancing antithombin III activity causing conformational change in ATIII exposing it reactive site
  • testing required to determine does effect on coagulation
  • not absorbed by GI tract due ti large molecular weight so either IV or SC injection
  • in log term treatment it is used until warfarin takes effect
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

HMW heparin therapy and adverse effects

A

Threputic use: venous thrombosis and pulmonary embolism , angina, acute MI

 - Does not cross placenta, perfect for pregnancy - Adverse effects: hemorrhage, osteoporosis and spontaneous fracture, 1-4% get heparin induced thrombocytopenia  - antagonist: protamine sulfate
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Monitoring HMW heparin

A
  • Activated partial thromboplastin time (aPTT) 25-39s
  • Threputic range 2-2.5x aPPT normal
  • Given IV every 6 hrs and monitored
  • SC injection usually not monitored
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

LMW heparin (pharmacology and therapy)

A
  • Fractioned form of HMW heparin(Dalteparin)
  • Inhibit factor Xa by antithrombin, too short to inhibit thrombin
  • Therapeutic uses: Venoous thrombolism, thrombosis, pulmonary embolism and unstable angina
  • protamine incompletely neutralizes LMW heparin
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Advantages of LMW heparin over HMW

A
  • Longer half-life(4 hrs) and faster absorption
  • much lower risk of thrombocytopenia and osteoporosis
  • once daily SC injection administered in outpatient setting
  • Less frequent monitoring required due to predictable PK
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Warfarin(Coumadin) pharmacology

A

Most widely used oral anticoagulant with predicable PK, bioavailability, and anticoagulant response.

  • blocks the carboxylation of glutamate residues in prothrombin and factors VII, IX and X.
  • The enzyme Vitamin K epoxide reductase is inhibited by warfarin preventing reductive metabolism of the inactive vitamin K epoxide to its active hydroquinone form
  • slow onset( 8-12hrs) existing clotting factors must be depleted maximal effect 3-5 day after administration.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Warfarin monitoring

A

Initiate: 5-10mg for one week to reach maintenance level, maintaince dose is 5-7 mg/d
-monitor prothrombin time to calculate INR

INR=((PT of patient)/(normal PT))^ISI

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

What is normal and therapeutic INR?

A

Normal INR= 1.0

Therapeutic INR= 2-3 times normal , 2.5-3.5 for tilting disk heart valves

17
Q

Warfarin Therapeutic uses and adverse effect.

A
  • Therapeutic uses: acute DVT, pulmonary embolism, venous thromboembolism, following acute MI, prosthetic heart valve placement, chronic atrial fibrillation
  • Adverse effects: hemorrhage, risk increases with intensity and duration. readily crosses the placenta
18
Q

warfarin drug interactions

A
  • increase effects : ASA, Anabolic steroids, antibiotics, tamoxifen, oral hypoglycemics, vitamin K deficiency.
  • Decrease effects: chronic alcohol abise, oral contraceptives, corticosteroids, barbituates, increased hepatic synthesis of clotting factors, increased vitamin K intake, Cholestyramine reduced bioavailability
  • Phytonadione(vitamin k1) used to reverse warfarin associated bleeding
19
Q

Warfarin dental considerations

A
  • May be continued for dental extractions
  • discontinue for oral surgery
  • Always check with MD before recommending discontinuation of warfarin
20
Q

Dabigatran etexilate pharmacology, therapeutic use and adverse effects

A

Direct Thrombin inhibitor

  • Standard oral twice-daily dose
  • Low molecular weight pro-drug, rapidly(1hr) converted to active form Dabigatran which binds to exosite 1 on thrombin preventing fibrinogen cleavage
  • Therapeutic effect : stroke prevention in atrial fibrillation- equal to warfarin
  • adverse effect: hemorrhage, heartburn, stomach upset, increase risk of MI
21
Q

Benfits and issues with Dabigatran etexilate

A

Benefit: no patient monitoring/ titration as with warfarin, rapid onset, no adverse drug reactions
-Issues: cost 10x more than warfarin in Europe . Approx. 30 million warfarin prescriptions in USA

22
Q

Thrombolytics pharmacology

A
  • Combine with plasminogen to make an active complex for conversion to plasmin
  • Or Directly convert plasminogen to plasmin
23
Q

Thrombolytics Theraputic uses, side effects, and inhibitors

A
  • therapeutics uses- in hospital : acute ischemic stroke, MI, Pulmonary embolism, severe deep venous thrombosis, ascending thrombophlebitis
  • Inhibitors: aminocaproic acid- inhibits the conversion of plasminogen to plasmin
  • Side effect- Hemorrhage
  • contraindicated for brain tumors or aneurysms, stroke, major surgey within last 2 weeks, active bleeding in GI or urinary tract, severe platelet shortage or coagulation disorder, severe uncontrolled hypertension
24
Q

Streptokinase Pharmacology

A
  • First thrombolytic available
  • Catalyzes the conversion of inactive plasminogen to active plasmin
  • Acts through the circulation, not just at the clot
  • Given IV ASAP after heart attack to dissolve clots in the arteries of the heart wall. only used in 1st heart attack
25
Q

Tissue plasminogen activator (tPA) Pharm

A
  • Endogenous thrombolytic; Human gene cloned, expressed and purified from bacteria
  • preferentially activates plasminogen that is bound to fibrin, which confines fibrinolysis to the formed thrombus and avoids systematic activation
  • acts on plasminogen only at site of clot !!
  • Effective in acute myocardial infarction

Pharm (10 decks)

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