Chapter 55: Anticoagulant, Antiplatelet, and Thrombolytic Drugs Flashcards
all drugs discussed in this chapter increase the risk of
patient bleeding
before administration of any of these drugs careful assessment of _____ should be completed to asses for internal bleeding
mental status, blood pressure, heart rate, and mucous membranes
henostasis stage 1
Formations of platelet plug
- platelet aggregation
Homostasis stage 2
Coagulation
- intrinsic coagulation pathway
- extrinsic coagulation pathway
what is a thrombosis
- blood clot formed within a blood vessel or within the heart
artrial thrombosis
- involves platelet adhesion to an arterial wall that causes atrial occlusion
Anticoagulants
- inhibit the action or formation of clotting factors
- prevent clot formation
Antiplatelet drugs
- inhibit platelet aggregation
- prevent platelet plugs
thrombolytic drugs
- Lyse (break down) existing clots
hemostatic drugs are also called
antibibrinolytic drugs
hemostatic drugs
- promote blood coagulation
non-thrombolytic drugs include
- unfractioned heparin and low molecular weight heparins (LMWHs)
- warfarin [Coumadin]
- rivaroxiban [Xarelto], Edoxaban [lixiana]
- dabigatrin [Pradaxa]
- apixaban [eliquis]
non thrombolytic drugs
prevent clot formation
- do not lyse clots
non-thrombolytic drugs also aid in the prevention of
- stroke
- myocardial infraction
- deep vein thrombosis
- pulmonary embolism
how do anticoagulants prevent clot formation
- reduce formation of fibrin
anticoagulants are used to prevent clot formation in
- myocardial infraction
- unstable angina
- atrial fibrillation
- indwelling devices, such as mechanical heart valves
- major orthopedic surgery
anticoagulants contradictions
- known drug allergy
- thrombocytopenia (low platelets)
warfarin is contradicted in
pregnancy
dabigatrin is contradicted in
nursing women
rivaroxaban, edoxaban is contradicted in
pregnancy and nursing
anticoagulants adverse events
- bleeding (risk increases with increased dosages; bleeding may be localized or systemic)
- nausea
- vomiting
- abdominal cramps
- thrombocytopenia
Unfractioned heparin (heparin sodium)
highly polar polysaccharide chain molecule
Unfractionated heparin MOA
enhances antithrombin
Unfractionated heprin reversal agent
Protamine sulfate
unfractionated heparin therapeutic uses
- pulmonary embolism
- massive deep vein thrombosis
- open heart surgery
- renal dialysis
- low dose therapy postoperatively
- disseminated intravascular coagulation
- adjunct the thrombolytic therapy
- atrial fibrilation complications
what is the preffered anticoagulant during pregnancy
unfractionated heparin
what is the preferred anticoagulant when rapid anticoagulation is required
unfractionated heparin
unfractionated heparin adverse effects
- hemorrhage
- heparin induced thrombocytopenia
- hypersensitivity reactions
unfractionated heparin is contradicted in
- thrombocytopenia (low platelets)
- uncontrolled bleeding
- recent surgery of the eye, brain, or spinal cord trauma
unfractionated heparin reversal agent
protamine sulfate
unfractionated heparin levels are measured by
activated partial thromboplastin time (aPTT)
heparin dose is measured in
units
what is normal aPTT
40 seconds
what is aPTT with heparin
60-80 seconds
low molecular weight heparin examples
enoxaparin
how is low molecular weight heparin diffrent from unfractioned heparin
- more predictable anticoagulant response
- do not require frequent labratory monitoring
- thrombocytopenia is rare
low molecular weight heparin measurements
products are in both UNITs and mg, depending on agent
- use caution
LMW heparins reversal agent
protamine sulfate
LMW heparins therapeutic use
- prevention of DVT after surgury (replacement of hip, knee, colorectal, abdominal, and gynecological)
- treatment of established DVT
- prevention of ischemic complications (unstable angina, non-Q-wave myocardial infraction, ST elevation MI (STEMI)
LMW heparins adverse effects
bleeding
anoxaparin [Lovenox] contains a preservative that is associated with potentially fatal
“gasping syndrome” in newborns or premature infants
Nadroparin Nadroparin (9500iu/ml) is used for
prophylaxis of thronboembolic disorders (DVT and PE) in general and orthopaedic surgery, treatment of DVT, prevention of clooting during hemodialysis, treatment of unstable angina and not Q wave myocardial infraction
Nadroparin (19000iu/ml) is used for
treatment of DVT
nadroparin can be used interchangeably with
unfracioned heparin or other LMW heparins
Warfarin MOA
vitamin K antagonist
- blocks biosynthesis of factors VII, IX, and X and prothrombin
Warfarin onset
delayed
- long half life
Warfarin [Coumadin] therapeutic uses
long term prophylaxis od thrombosis
Warfarin is administered
orally
what should be monitored after Warfarin administration
prothrombin time (PT) and International normalized ratio (INR) (PT/INR)
what is normal international normalized ratio
1.0
warfarin international normalized ration
2-3.5
warfarin is bound to
99% protein bound
Warfarin [Coumadin] adverse effects
- severe bleeding, including heavier than normal menstrual cycle or gums after brushing
- red or brown urine
- black or bloody stool
- severe headache or stomach pain
- joint pain, discomfort or swelling, especially after injury
- easy brusing
- dizziness or weakness
warfarin [Coumadin] drug interactions
- drugs that increase anticoagulant effects
- drugs that promote bleeding
- drugs that decrease anticoagulant effects
what are warfarin herbal interactions
- capsicum pepper
- feverfew
- garlic
- ginger
- ginko
- ginseng
how long do warfarin’s full therapeutic efects take
several days
what is the antidote to warfarin
vitamin K
what should nurses monitor for in a patient taking warfarin
bleeding or bruising
Direct thrombin inhibitors example
Dabigatran etexilate [pradaxa]
advantages of direct thrombin inhibitors
- rapid onset
- dont require monitoring of anticoagulation
- lower risk of adverse interactions
- few food drug interactions
- same dose can be used for all patients regardless of age or weight
Dabigatrin therapeutic uses
atrial fibrilation, VTE prophyaxis
Argatroban therapeutic uses
prevention of DVT in patients undergoing elective hip replacement surgury
Direct thrombin inhibitors adverse effects
- bleeding
- GERD, dyspepsia, nausea and vomiting, bloating)
reversal agent for dabigatrin
idarucizumab [praxiband]
Direct factor Xa inhibitors
rivaroxaban [xarelto]
- Apixaban [eliquis]
- edmoxaban [lixiana]
rivaroxaban [xarelto] should bu used in caution in
renal/hepatic impairment, pregancy
Direct factor Xa inhibitors use
- prevention of DVT and PE after total hip or knee replacement surgery
- prevention of stroke in patinets with atrial fibrillation
- treatment of DVT and PE unrelated to orthopedic surgury
Direct FActor Xa Inhibitors seide effects
- bleeding
- itching
Antiplatelet drugs example
Acetylsalicylic acid [asprin]
Clopidogrel [Plavix]
- Dipyridamole [Persentine}
Acetylsalicylic acid [asprin] MOA
inhibition of cyclooxygenase
Acetylsalicylic acid [asprin] adverse effects
- increases risk for bleeding, especially GI bleeding, hemorrhage stroke
Acetylsalicylic acid [asprin] therapeutic uses
- ischemic stroke
- transient ischemic attacks (TIA)
- chronic stable angina
- unstable angina
- coronary stenting
- acute MI
- primary prevention of MI
Clopidogrel [Plavix] should be used with caution in
combination with other drugs that promote bleeding
Dipyridamole [persantine] is used
after valve replacement
a combination of dipyridamole and asprin is used to
- prevent recurrent ischemic stroke in patients who had previous stroke or TIA
a combination of dipyridamole and asprin adverse effects
GI upset, bleeding, headache, dizziness
Thrombolytics example
Alteplase
- streptokinase [streptase]
- anisterplase [eminase]
- reteplase [retavase]
- tenecteplase [TNKase]
- drotrecogin alfa [Xigris]
Alteplase therapeutic uses
- myocardial infraction
- ischemic stroke
- massive pulmonary emboli
Alteplase contradictions
drug allergies, other drugs that alter clotting
Alteplase adverse effects
bleeding
Alteplase advantages
- does not cause allergic reactions
- does not induce hypotension
Antithrombolytic drugs MOA
prevent breakdown of fibrin by preventing the formation of plasmin
- used for uncontrolled bleeding in the mucous membrane of the mouth, nose and throat and dental extractions
Antithrombolytic drugs examples
- Aminocaproic acid
- tranexamic acid
tranexamic acid is used primary for
heavy menstrual bleeding
