Antiplatelet & Anticoagulant Meds Flashcards
clopidogrel - MOA
*oral antiplatelet: decreases platelet aggregation via P2Y12 receptor inhibition (irreversible)
*blocks ADP (P2Y12) receptor → decreased ADP-induced expression of GpIIb/IIIa
prasugrel - MOA
*oral antiplatelet: decreases platelet aggregation via P2Y12 receptor inhibition (irreversible)
*blocks ADP (P2Y12) receptor → decreased ADP-induced expression of GpIIb/IIIa
ticagrelor - MOA
*oral antiplatelet: decreases platelet aggregation via P2Y12 receptor inhibition (REVERSIBLE)
*blocks ADP (P2Y12) receptor → decreased ADP-induced expression of GpIIb/IIIa
aspirin - MOA
*oral antiplatelet: decreases platelet aggregation via thromboxane A2 (TXA2) inhibition
*IRREVERSIBLY blocks COX → decreased TXA2 release
clopidogrel - uses
*acute coronary syndrome (ACS) [med management or PCI/stent]
*peripheral artery disease (PAD)
*thrombotic stroke
prasugrel - uses
*acute coronary syndrome (ACS): PCI/stent
ticagrelor - uses
*acute coronary syndrome (ACS): med management or PCI/stent
aspirin - uses
*acute coronary syndrome (ACS)
*chronic stable angina
*stroke prophylaxis
*peripheral artery disease (PAD)
clopidogrel - ADEs
*bleeding
*RASH
*TTP
prasugrel - ADEs
*bleeding
*rash
*AVOID USE in: TIA/STROKE; age > 75; or < 60kg
ticagrelor - ADEs
*bleeding
*dyspnea
*increased serum creatinine
*increased uric acid
aspirin - ADEs
*bleeding
*GI upset
*angioedema
*gastric ulcers
*tinnitus
*allergic reactions
*renal injury
*Reye syndrome (in children)
drug effectiveness in platelet aggregation inhibition: aspirin vs. clopidogrel, prasugrel, ticagrelor
*clopidogrel/prasugrel/ticagrelor > aspirin
*clopidogrel/prasugrel/ticagrelor are MORE EFFECTIVE AT INHIBITING PLATELET AGGREGATION compared to aspirin
dipyridamole - MOA
*oral anti-platelet: decreases platelet aggregation
*inhibits platelet adenosine deaminases & phosphodiesterases → decreased cAMP hydrolysis and increased cAMP in platelets
dipyridamole - ADEs
*dizziness
*headache
*GI upset
cilostazol - MOA
*oral antiplatelet: decreases platelet aggregation
*inhibits platelet phosphodiesterase-III → decreased cAMP hydrolysis and increased cAMP in platelets
cilostazol - ADEs
*dizziness
*headache
*GI upset
*edema
*palpitations
vorapaxar - MOA
*oral antiplatelet: decreases platelet aggregation
*inhibits thrombin & thrombin receptor agonist peptide (TRAP) at PAR-1 receptor
vorapaxar - ADEs
*bleeding
*rash
abciximab - MOA
*IV antiplatelet
*glycoprotein IIb/IIIa inhibitor: monoclonal antibody
eptifibatide - MOA
*IV antiplatelet
*glycoprotein IIb/IIIa inhibitor: peptide
tirofiban - MOA
*IV antiplatelet
*glycoprotein IIb/IIIa inhibitor: non-peptide
abciximab - ADEs
*bleeding
*thrombocytopenia
eptifibatide - ADEs
*bleeding
*thrombocytopenia
tirofiban - ADEs
*bleeding
*thrombocytopenia
cangrelor - MOA
*IV antiplatelet
*REVERSIBLE P2Y12 INHIBITOR
cangrelor - ADEs
*bleeding
*dyspnea
unfractionated heparin (UFH) - MOA
*activates antithrombin III → inhibition of thrombin (IIa), IXa, Xa, XIa, and XIIa
*used for immediate ANTICOAGULATION
note - does not affect clot-bound thrombin or platelet-bound factor Xa
enoxaparin - MOA
*low-molecular-weight heparin
*acts mainly on factor Xa (and a bit on IIa)
*long-term anticoagulant of choice in pregnancy!
fondaparinux - MOA
*anticoagulant that inhibits factor Xa only
*must bind to antithrombin III to exert pharmacologic activity
*black box warning: increased risk of epidural/spinal hematomas with neuraxial anesthesia
heparins - ADEs
*monitor PTT
*bleeding
*decreased platelets
*HIT/HITT
direct thrombin inhibitors - bivalirudin, argatroban
*MOA: directly inhibits factor IIa (thrombin)
*bind free AND clot-associated thrombin
note - significantly more expensive than IV heparin
bivalirudin - drug class/MOA
*directly inhibits thrombin (IIa)
monitor serum creatinine
argatroban - drug class/MOA
*directly inhibits thrombin (IIa)
monitor LFTs
protamine sulfate
*REVERSAL AGENT FOR HEPARIN anticoagulants
*alkaline protein molecule
*binds heparin & reverses anticoagulant activity
*partially reverses low-molecular-weight heparin anticoagulant activity
note - does not reverse fondaparinux or direct thrombin inhibitors
heparin-induced thrombocytopenia - types
*type 1: mild, transient thrombocytopenia
*type 2: autoantibodies against heparin-platelet factor 4 (PF4) complex → thrombosis
heparin-induced thrombocytopenia - diagnosis
*onset 5-10 days after heparin initiation
*platelets decrease 50%+
*new thrombosis
*(+) platelet factor 4 heparin antibody, serotonin release assay
heparin-induced thrombocytopenia - management
*STOP heparin products
*switch to DTI or fondaparinux for anticoagulation
*treat at least 4 weeks; if thrombosis, 3 months
*note heparin allergy
warfarin - MOA
*anticoagulant: vitamin K epoxide reductase inhibitor
*prolongs clotting time by inhibiting synthesis of vitamin K-dependent factors (II, VII, IX, and X)
*inhibits proteins C & S
note - must bridge warfarin with another anticoagulant b/c of half-life of vitamin-K dependent clotting factors
warfarin - goals of therapy
*anticoagulant effects monitored by INR (PT)
*monitoring frequency influenced by many factors (time since last dose change, stability of INR, etc)
warfarin - ADEs
*bleeding
*lots of drug interactions (most of which increase the effects of warfarin, leading to increased bleeding risk)
*food interactions (foods with high vitamin K content can affect INR)
reversal agents for warfarin
- vitamin K - promotes synthesis of clotting factors; delayed response
- fresh frozen plasma (FFP) - contains factors II, VII, IX, X
- prothrombin complex concentrates - FEIBA or Kcentra; preferred for emergent or life-threatening reversal; must be administered with vitamin K!
direct oral anticoagulants (DOACs) - examples
- dabigatran (direct thrombin inhibitor)
- factor Xa inhibitors: rivaroxaban, apixaban, edoxaban, betrixiban
direct oral anticoagulants (DOACs) - advantages over warfarin
*quick onset/offset
*fewer drug interactions
*minimal food interactions
*more predictable dosing
*decreased monitoring (CBC, serum creatinine)
direct oral anticoagulants (DOACs) - reversal agents
- prothrombin complex concentrates - FEIBA and Kcentra
- idarucizumab - human monoclonal antibody; binds dabigatran; ineffective in binding other direct thrombin inhibitors
- andexanet alfa - modified human factor Xa molecule; binds direct and indirect factor Xa inhibitors