PAD Flashcards
What is the main cause for PAD?
Smoking or DM have greatest risk
What are the 2 complications of PAD?
- Critical limb ischemia
2. Stroke and Heart Attack
What can pseudoephedrine and OTC meds predispose you to?
Vasoconstrict so bad in PAD
What is found on physical exam of PAD?
ABI < 0.9
Weak or absent pedal pulses with bruit
Poor wound healing
Tredmill test is positive to assess severity while walking
Note that with DVT we will see swelling, pain, red/discolored skin, warmth
What are the tests to check PAD dx?
- Ultrasound = identify blocked arteries
- Angiography = view blood flow
- Blood tests = lipid, fasting glucose
This med is a type 3 PDE inhibitor that prolongs the life of cAMP in platelets and cells to promote aggregation and vasodilate
Cilostazol
When is Cilostazol contraindicated?
Heart failure patients - especially Class III and IV patients
What imaging can be done for DVT dx?
Ultrasound
Blood Test = D-dimer
Venography = visualize via Xray
CT/MRI
What are the only 3 oral drugs for DVT treatment? Rest are parenteral
Warfarin, thrombin inhibitor, factor Xa inhibitor
Can also treat with compression stockings, stents, and vena cava filter
Antiplatelet drugs break up
white clots
Anticoagulant drugs block. Complication?
red clots (fibrin)
Spinal or epidural hematoma
Intrinsic pathway is represented by:
aPTT - we mix phospholipids, activator, and Ca2+ in the patient’s plasma and evaluate serine protease factors (2, 9, 10, 11, 12)
HEPARIN
WAR IS OUTSIDE SO HEPARIN MUST BE INSIDE
Extrinsic pathway is represented by:
PT - time to coagulation after addition of tissue factor - then normalized to INR
WARFARIN you lose lots of tissue
Use this drug to treat RAPIDLY for PE, Stroke, DVT, DIC, acute MI
Heparin
MOA of heparin?
Binds to and activates antithrombin III to inhibit factor Xa then thrombin
This drug prevents formation of red clots
Heparin
Can heparin be used in pregnancy?
yes
When is heparin contraindicated?
- Thrombocytopenia
- Uncontrollable bleeding
- Avoid using during any surgery or procedure involving CNS or eyes (also enoxaparin)
- BLEEDING IS HUGEST CONCERN
What does enoxaparin and fondiparinaux inhibit?
LMWH - inhibits Factor Xa
This drug is used for prevention DVT after abdominal surgery or hip/knee replacement
Enoxaparin
This drug is used for ischemic pcomplications in unstable angina or STEMI
Enoxaparin
What is the first choice for treatment and prevention of DVT?
Enoxaparin, much longer half lives and dosing is predictable
What is the antidote to enoxaparin?
Protamine
This drug is used to treat PE or DVT with warfarin
Fondiparinaux
This is an anticoagulant that must be stopped 4-5 days before surgery
Fondiparinaux
What anticoagulant is not reversible by protamine?
Fondiparinaux
This drug does not cause heparin induced thrombocytopenia
Fondiparinaux
The benefit to using bivalirudin over heparin?
Doesn’t need antithrombin and causes less bleeding, but there’s no antidote
This drug is given in combination with aspirin for angioplasty patients
Bivalirudin
What’s the difference in MOA of bivalirudin and trobin?
Bivalirudin = directly blocks thrombin Argatroban = directly binds catalytic site of thrombin
How do we monitor if argatroban is working?
Monitor aPTT
What is the challenge associated with warfarin dosing?
Genetic variability
Note that the CYP2C9 substrate is S-warfarin and polymorphisms of this in whites lead to lower clearance rates
What makes warfarin resistant in blacks but sensitive in asians?
VKORC1 haplotype
This drug is used for long-term prophylaxis of thrombosis in mechanical heart valves, PE, atrial fibrillation, but cannot be used in emergencies
Warfarin
How do we monitor warfarin?
It’s 100% bioavailable orally but it is eliminated by liver in bile, has slow onset and slow offset
We monitor with PT, INR = 2-3, and check more frequently if you add or subtract a drug
What happens when bleeding occurs with warfarin?
Discontinue warfarin immediately and administer Vitamin K to reverse
Why do we get cutaneous necrosis with warfarin?
Protein C has a shorter half life than several other clotting factors so pro-coagulant state initially
This drug can be used to prevent DVT and PE after hip/knee replacement and prevent stroke in patients with nonvalvular atrial fibrillation
Rivaroxaban
Note that mechanical heart valves are contraindicated in Dabigatran
What can we use as an antidote to rivaroxaban?
Andaxanet alfa
What drug must be kept in a supplied dessicator bottle?
Dabigatran
General concern with all anticoagulants in terms of adverse effects
Bleeding and cranial issues
