Shared Flashcard Set

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Blood disorders' drugs
board prep
19
Medical
Graduate
05/03/2008

Additional Medical Flashcards

 


 

Cards

Term

 

 

 

Warfarin (MOA)

Definition

Inhibits the hepatic synthesis of vitamin K dependent factors II, VII, IX, X, by inhibiting vit. K epoxide reductase --> prevention of gamma carboxylation of factors

 

NO effect on already present factors therefore slow onset 

Term

 

 

 

Heparin (MOA)

Definition
Inhibits the activity of several activated clotting factors including IIa, IXa, Xa, Xla, XIIa via the action of antithrombin III (rapid inactivation!!)
Term

 

 

 

Protein C and S

Definition
Endogenous anticoagulants that cause proteolysis of factors Va and VIIIa
Term

 

 

 

Heparins

Definition

Chemical make-up: water soluble

 

kinetics: given IV/SC, short 1/2 life, hepatic/RES metabolism, CAN'T X placenta

 

Monitor: PTT, partial thromboplastin time

 

Antidote: protamine sulfate

Uses: rapid anticoagulation for thromboses, emboli, unstable angina, DIC, open-heart surgery

 

Toxicity: bleeding, osteoporosis, heparin-induced thrombocytopenia (HIT), hypersensitivity

 

 

 

Term

 

 

 

Warfarin

Definition

Chemical makeup: small, lipid soluble derivative of vit. K

Kinetics: oral, 98% protein bound, liver metabolism, long 1/2 life, CAN X placenta

 

Monitor: PT (prothrombin time); INR

 

Antagonist: Vitamin K, increases cofactor synthesis, can also give fresh frozen plasma

 

Uses: long-term anticoagulation for thromboses, emboli, post MI, heart valve damage, atrial arrhythmias

 

Toxicity: bleeding, skin necrosis, drug interactions, teratogenic (bone dysmorphogenesis) 

 

 

Term

 

 

 

Enoxaparin

Definition

MOA: low-molecular weight heparin that has longer half life

 

Uses: causes less thrombocytopenia, and enhanced activity of factor Xa

Term

 

 

 

Drug interactions w/ Warfarin

Definition

Acidic molecule so when pt takes cholestyramine (or anything that makes stomach less acidic) causes decreased absorption

 

Extensive/weak protein binding: and can be displaced by MANY other drugs which will increase the free fraciton (ex: ASA, sulfonamide, phenytoins etc.)

 

Slow hepatic metabolism via P450 so:

inducers --> dec. activity

inhibitors --> inc. activity

Term

 

 

 

Protein C def.

Definition

Normally protein C activates S which can then inactivate factors Va and VIIIa

 

If there is no protein C --> hypercoagulation

Term

 

 

 

Bivalirudin

Definition

MOA: thrombin-specific anticoagulant

 

Uses: w/ ASA in unstable angina when undergoing percutaneous transluminal coronary angioplasty

Term

 

 

 

Thrombolytics (MOA)

Definition

aka fibrinolytics, tissue plasminogen activator & streptokinase

 

Lyse thrombi by catalyzing the formation of the endogenous fibrinolytic plasmin (serine protease) from its precursor plasminogen 

Term

 

 

 

Streptokinase

Definition

Uses: IV for short-term EM management of coronary thromboses in MI, DVT, PE, and ischemic stroke

 

MOA: acts on both bound and free plasminogen (NOT clot specific) depleting circulating plasminogen and factors V and VIII

 

It is a foreign protein (made from beta hemolytic streptococci) so can be ineffective if had recent infxn where Abs were formed

Term

 

 

 

Alteplase

Definition

aka tissue plasminogen activator

 

Uses: clot specific, acts mainly on fibrin-bound plasminogen

Term

 

 

 

Clinical features of thrombolytics

Definition

Effective if EARLY administration (60% decrease in mortality if used w/in 3hrs post MI)

 

ASA, beta-blockers, and nitrates further dec. mortality and adenosine dec. infarct size

 

complications can include intracerebral hemorrhage

 

Antidotes: aminocaproic & tranexamic acids (antifibrinolysins)

Term

 

 

 

Clot formation

Definition

1. Platelet adhesion to injury site

2. Activation of platelets by (TxA2, ADP, collagen, 5HT, and thrombin) --> inc. expression of glycoprotein IIb/IIIa receptors

3.  Aggregation of platelets by a cross-linking rxn d/t fibrinogen binding to glycoprotein IIb/IIIa receptors

Term

 

 

 

What increases platelet aggregation

Definition
ADP, 5HT, TxA2, thrombin, alpha 2 agonists
Term

 

 

 

What decreases platelet aggregation

Definition
PGI2, cAMP, ASA, ticlopidine, clopidogrel, glycoprotein IIb/IIIa blockers
Term

 

 

 

Aspirin

Definition

MOA: irreversibly inhibits COX in platelets --> dec. activation

 

Uses: low doses prevent MI and recurrence, prophylaxis in atrial arrhythmias and TIAs

Term

 

 

 

Ticlopidine and Clopidogrel

Definition

MOA: block ADP receptors on platelets --> dec. activation

 

Uses: alternatives to ASA in TIAs, post-MI, and unstable angina

SE: hemorrhage, leukopenia, and thrombocytopenic purpura

Term

 

 

 

Abciximab, eptifibatide, and tirofiban

Definition

MOA: antagonists that bind glycoprotein IIb/IIIa receptors --> dec. aggregation by preventing the cross-linking rxn

Uses: acute coronary syndromes (unstable angina) and postangioplasty

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