Anticoagulant, Antiplatelet and Thrombolytic Drugs Flashcards
state the difference between antIcoagulant drugs and AntiplAtelet drugs
antIcoagulant drugs are drugs that are given to reduce formation of fIbrIn (the meshwork that makes up clots)
antiplatelet drugs are given to suppress platelet Aggregation.
state the main difference between a thrombus and an embolus
a thrombus is defined as a blood clot formed within a blood vessel or within the heart.
An embolus is anything that moves through the blood vessels until it reaches a vessel that is too small to let it pass. When this happens, the blood flow is stopped by the embolus. An embolus is often a small piece of a blood clot that breaks off (thromboembolus).
summarize the differences between anticoagulants warfarin and heparin: mechanisms, onset, sites of action, and monitoring
mechanisms and onset
heparin mechanism: helps antithrombin neutralize clotting factors (thrombin and Xa)
warfarin mechanism: helps by decreasing production of four vitamin K dependent clotting factors (VII, IX, X, prothrombin).
Warfarin inhibits vitamin K epoxide reductase, the enzyme needed to convert vitamin k to the required activated form.
heparin onset: therapy is sometimes initiated with a bolus dose and effects begin immediately.
warfarin onset: noticeable anticoagulant effects are delayed (but still present)
summarize the differences between anticoagulants warfarin and heparin:
mechanisms, onset, sites of action, and monitoring
ANTIDOTE FOR EACH?
warfarin MOA: blocks clotting factors dependent on vitamin K–Warfarin WARS against vitamin K
heparin MOA: works with anti-thrombin against thrombin
heparin sites of action: plasma
warfarin sites of action: in the blood
heparin monitoring: use activated partial thromboplastin time along with anti-factor Xa Heparin Assay. use both continuously/frequently until an effective dose has been established for the patient.
warfarin monitoring: INR-PT test every few weeks, every week, whatever the doctor wants.
ANTIDOTE–warfarin: vitamin K
ANTIDOTE–heparin: protamine sulfate
describe the lab tests to be performed with monitoring and bleeding issues with anticoagulants (CBC, INR/PT, aPTT, platelets)
CBC: complete blood count-measures how much of each component of blood is there
INR-PT: measures the prothrombin time against a international normalized ratio to make sure it’s within the right range. 2-3 for healthy people, but for some people the goal is 2.5 to 3.5. IF INR below recommended range, dose should be increased.
aPTT: also measures prothrombin time. normal value is 40 seconds. heparin can increase this to 60-80 seconds. More worrisome if it’s too low.
platelets: making sure there is no thrombocytopenia and etc.
list the uses of low molecular weight heparin
prevention and treatment of DVT following hip surgery, abdominal surgery, hip or knee replacement surgery
treatment of established DVT, w/ or w/o PE
prevention of ischemic complications in patients with unstable angina
contrast heparin with lovenox.
heparin has all of it’s molecules, and lovenox is essentially the same thing as heparin, but it is a low molecular weight heparin.
This means that they took regular heparin and depolymerized it, thus reducing the molecular weight.
There are a little more limited therapeutic uses: prevention of DVT following abdominal surgeries, treatment of DVT with or without PE, and prevention of ischemic complications in patients with unstable angina.
heparin is used for: pregnancy (safe to use in pregnancy), PE, DVT, for patients undergoing open heart surgery and renal dialysis, also prevention of post op DVT.
lovenox can cause immune mediated thrombocytopenia.
explain situations when taking warfarin and aspirin is dangerous and include the age impact and organ dysfunction.
adding aspirin to an anticoagulant regimen is dangerous because it can put the patient at a higher risk of bleeding.
age: the older someone is, the more careful you have to be.
organ dysfunction: if certain organs don’t function well (liver, etc.), then you also have to be careful
contrast aspirin with clopidogrel as platelet inhibitors
aspirin suppresses platelet aggregation by causing irreversible inhibition of COX, clopidogrel irreversibly blocks recetors for ADPa.
Aspirin is a primary preventer of MI, clopidogrel is a secondary preventer of MI.
summarize nursing implications in teaching patients taking heparin and warfarin
provide the patient with detailed verbal and written instructions regarding the purpose of treatment, dosage size and timing, and the importance of careful adherence to the dosing schedule.
advise the patient to avoid prolonged immobility, elevate the legs when sitting, avoid garments that can restrict blood flow in the legs, participate in exercise activities, and wear support hose.
warn patients about the dangers of hemorrhage, and have them notify the provider if any signs, including, but not limited to: reduced bp, elevated hr, discolored urine or stools, petechiae, hematomas, persistent headache or faintness (cerebral hemorrhage), pelvic pain (ovarian hemorrhage), and lumbar pain (adrenal hemorrhage). have patients also wear a medical alert bracelet or have some indication that they are on warfarin or heparin for first responders.
advise patient to avoid excessive consumption of alcohol. use a soft toothbrush to prevent bleeding from the gums. advise patients to shave with an electric razor. instruct the patient to make sure the surgeon is aware of warfarin or heparin use if they have surgeries.
inform those of childbearing age that it could cause fetal injury, and warn them against breast feeding as it could get into the milk.
discuss the transition to novel anticoagulants
NOACs interrupt part of the complex system involved in the formation of blood clots. This causes the blood to take longer to clot and reduces the risk of AF-related stroke. All of the NOACs have been shown to be as effective at preventing strokes as warfarin. The main difference between NOACs and warfarin is that NOACs are less influenced by diet and other medications.
For this reason, some providers are transitioning to them, especially when it makes sense for the patient.
what signs and symptoms would you look for to monitor for bleeding while someone is on anticoagulant therapy?
reduced bp, elevated hr, discolored urine or stool, brusies, petechiae, hematomas, persistent headache or faintiness, pelvic pain, lumbar pain
