Pharm 6 Thrombi pt1 Flashcards
Example of Anticoagulant Drugs
Route of admin?
Heparin (IV)
What does Heparin do?
What doesn’t it do?
Reduces the likelihood of the formation of new thrombi.
Doesn’t involve the synthesis of clotting factors and cannot dissolve existing clots
Heparin’s IV dosing requires ____. Why?
IV dosing requires regular monitoring of PT/PTT/INRs, frequent adjustment of dosing
B/c of many factors ppl respond differently to it.
how it’s metabolized, endothelial linings unique to your blood vessels, weight, gender, renal function, other drugs you’re on, and foods you eat.
Heparin’s FDA indications (5)
Prevention or treatment of DVTs
Prevention or treatment of pulmonary emboli
Treatment of disseminated intravascular coagulation resulting in dysfunction of the clotting cascade
Treating arterial clotting and prevention of embolus formation in patients with atrial fibrillation
Preventing thrombus formation and promoting cardiac circulation in acute coronary syndromes by preventing clot propagation of existing clots
What is the better way to dose Heparin?
dosed using weight-based regimen
Heparin Clinical Pearls
Can be used to prevent clotting when blood circulates through mechanical tubing outside the body (i.e., during surgery involving cardiac bypass and hemodialysis treatments)
Useful to prophylax against clotting during surgeries that involve high risk of thrombus formation (i.e., orthopaedic surgery and recovery)
How to reverse Heparin’s risk of bleeding with overuse/misuse.
*Adding protamine sulfate (mix an acid and a base) makes water and salt. No more anticoagulant in the bloodstream.
What’s the big difference between LMWH and Heparin?
Reacts the same for everybody, unlike Heparin.
LMWH
Example, Route of Admin
FDA approved for (3)
Enoxaparin (SQ)
DVT prophylaxis in orthopedic surgeries, abdominal surgery or immobilized patient at risk for DVT
Treatment of DVT with or without PE
To prevent ischemic complications of ACS, unstable angina and non-Q-wave AMI
How many hours to become therapeutic with Heparin? How about Enoxaparin?
72 hours with Heparin
11 hours with Enoxaparin
The plan to treat DVT patient with Enoxaparin
Give them 1 shot of Enoxaparin, wait 11 hours for them to be therapeutic & watch them, then send ‘em home. It’s also good to have them in their own home, walking around b/c the DVT occurred while you were being immobile on an airplane, or something. A send-home nurse can give follow up
Where is Warfarin absorbed?
What is it derived from?
Absorbed rapidly through GI tract
Derived from clovers
8 FDA approved indications for Warfarin
Thromboembolic disorders DVT prophylaxis PE prophylaxis Atrial fibrillation Prior ischemic CVA Recurrent ACS and AMI Post-AMI Bio-prosthetic heart valves
How does Warfarin work?
How immediately does it work, why?
Alters the liver’s ability to synthe`size vitamin-K dependent clotting factors
Clotting factors already in the bloodstream continue to coagulate normally until they become depleted (~5 days) so anticoagulation does not begin immediately
What test sees if the benefit of Warfarin outweighs the risk?
CHAD-2 scores
What may REDUCE effectiveness of Warfarin?
Diets high in vitamin K (green, leafy vegetables, esp. spinach)
Dabigatran
Route of admin?
What is it approved for? (1)
What’s good & bad about it?
Dabigatran PO
Approved for A Fib without valvular disease
don’t need to have monthly blood drawn. But: It chews up your platelets as long as it’s in blood. Even if you give more plasma/platelets, it chews it up still. For 5 days. If there’s a bad accident (motorcycle accident)/anything that puts you at risk for bleeding, you won’t be able to stop the bleeding, especially bad for an intracranial hemorrhage.
Risks & Benefits of Apixaban (2)
Prevents ~ 3 more strokes than Warfarin
Leads to 10 fewer bleeds and 4 fewer deaths
Risks & Benefits of Dabigatran (3)
Prevents ~ 5 more strokes than Warfarin
Similar bleeding risk to Warfarin
Only new agent proven to reduce both ischemic and hemorrhagic CVAs
Risks & Benefits of Rivaroxaban (3)
Prevents fewer strokes than Warfarin
has similar bleeding risk
(less blood drawn)
Name the 3 newer Oral Anticoagulants
Do NOT use newer agents for patients with:
Apixaban
Dabigatran
Rivaroxaban
Do NOT use with patients with Mechanical Heart Valves
4 reasons you should not feel compelled to switch patients off Warfarin.
- If INR’s are stable while on Warfarin
- B/c Warfarin has an antidote, other agents do not
- Warfarin costs less per month, and has once monthly INR monitoring
- Warfarin is once daily dosing
If you have a reason to go away from Warfarin (can be allergic to Warfarin), Lean to ___ and ___.
Why?
dabigatran or apixaban because they prevent more strokes
Apixaban for patients who need once daily dosing
Use of Antiplatelet drugs
In patients at risk for what? (4)
Used to prevent arterial thromboembolism, particularly in patients at risk for AMI, ACS, CVA, atherosclerosis
Key Antiplatelet drug
aspirin
