Chapter 46: anticoagulants And Antiplatelet Drugs Flashcards
3 types of blood thinners
Anticoagulants, antiplatelets, trombolytics
Anticoagulants
Used to inhibit clot formation
Used with thromboembolism treatment or thromboembolism prophylaxis
Venous
Deep vein thrombosis (DVT)
Pulmonary embolism (PE)
Arterial
Coronary thrombus (MI) -Lead to MI
Presence of artificial heart valves
Stroke
3 classes of anticoagulants
Drugs that Activate Antithrombin
Need thrombin to create clot
Heparin
Enoxaparin (Lovenox)
Vitamin K Antagonist
Warfarin
Factor Xa Inhibitors
Rivaroxaban (Xarelto)
Apixiban (Eliquis)
Tabigatrin is a factor 10a inhibitor but is not used as frequently, not as effective
Unfractionated heparin MOA
Rapid acting AC that Inactivates thrombin. Prevent further clot formation.
Heparin use
Indicated for rapid anticoagulant effect for thromboembolism treatment or prophylaxis
Introduced in 1938
Heparin route
IV or Sub Q (injection ONLY)
Heparin SE
Bleeding, HI thrombocytopenia, prolonged clotting time
HIT potentially fatal, immune mediated disorder. Characterized by decrease plt. Monitor plt on heparin, if plt drops d/c hep. If pt still needs anticoagulant therapy, give non-heparin anti-coagulant –typically gatroban. HIT can occur in ~5% of pt who are on hep for >4 days.
Normal aPTT 35 sec. Therapeutic aPTT is 70 sec
Heparin Ssaftey and monitoring
Monitor PTT (Partial thromboplastin time) OR aPTT (activated partial thromboplastin time) . Therapeutic value is 2X normal
Safe in pregnancy
Heparin antagonist
Protamine Sulfate
Heparin d/c
When discontinued, oral AC is started
LMWH
Enoxaparin sodium (Lovenox)
This is a heparin prep. Prep with shorter molecules than what heparin has. Just as effective as unfractionated heparin
More convenient, can be admin at home, les SE -1st line tx for DVT prevention
LMWH MOA
Binds to AT III to inactivate thrombin
LMWH use
DVT prophylaxis, DVT/PE, Prevention of ischemia for angina unstable and MIs
More convenient, can be admin at home, les SE -1st line tx for DVT prevention
LMWH route
*SC only. Dosage based on body weight and administered BID
LMWH SE
bleeding, thrombocytopenia
Can cause HIT, but less than UFH
LMWH safety and monitoring
May be given at home, monitor platelets
Contraindicated in clients with hem strokes, peptic ulcers. Not given after eye, brain or spinal surgery
Cautious in pt with RF, pretty much contraindicated in pt with renal probs
Warfarin MOA
Inhibit synthesis of vitamin K
Warfarin use
DVT/PE, VTE prophylaxis, atrial fib/flutter, ischemic stroke
Delayed onset –not appro for emergency
Warfarin route
PO
Warfarin labs
Monitor PT prothrombin time and INR international normalized ratio
Desired INR when on warfarin is 2x normal
PT/INK –in order to get INR, need PT first. Normal INR is 1-1.5, therapeutic is going to be 2-3. Toxic is over 3 -> bleed.
Warfarin SE
Bleeding is a major side effect (Monitor for signs of bleeding)
Petechiae
Ecchymosis
Hematemesis, occult stool, hematuria, epistaxis
Bleeding gums
Warfarin safety and monitoring
Antidote is vitamin K
Does not work immediately =, often will give with FFP (has clotting factors in it)
Diet education is necessary
green leafy veg, keep intake consistent
Want to avoid fluctuations
Many drug interactions
DOAC: factor Xa inhibitors
rivaroxaban (Xarelto)
apixiban (Eliquis)
DOAC MOA
Selectively blocks Factor Xa (factor Xa inhibitor)
DOAC use
DVT/PE, VTE, atrial fib/flutter treatment, DVT and stroke prophylaxis. Convienent –no dietary restrictions, no routine monitoring
DOAC SE
Bleeding
DOAC safety and monitoring
Routine coagulation monitoring not required
Reversal agents are available now
Expensive reversal agents, can give FFP
Not safe in preg
Antiplatelet MOA
Used to prevent thrombosis in the arteries by suppressing platelet aggregation
antiplatelet use
Prevention of thrombosis in arteries. Indications:
Prevention of MI or stroke in patient with family history or high risk factors.
Prevention for a repeat MI or stroke
Prevention of a stroke in patients having TIAs.
TIA pt will have stroke within 6 Mon
Angina- To reduce the risk of death
Coronary stenting- To prevent occlusion
Antiplatelet ASA
ASA can greatly reduce morbidity and mortality for Mis, stores, TIAs, angina. If pt needs ASA and gets GI upset, add PPI
81 mg, or 325 mg/day
ASA SE: GI Bleed and hemorrhagic stroke.
Anti platelet clopidogrel (Plavix)
Use: ASA allergy. Prevents stenosis of coronary stents
SE: Bleeding, TTP
Antiplatelet cilostazol (Pletal)
Use: Antiplatelet; Claudication
Inhibits platelet aggregation and is a vasodilator. Indicated for PVD and intermittent claudication
Works better than ASA for PVD
Antiplatelet naturals
Garlic, ginkgo, ginger increase bleeding especially when taken with anticoagulants
Increase bleeding time
Anti-platelet contraindications
Contraindicated if someone is purposely bleeding. Hold prior to sx, no routine mentoring, use caution with other meds that promote bleeding like NSAIDs, ASA + nticoag, may see ASA and plt is together for stent
