drugs used for PAD and DVT Flashcards
(50 cards)
What are the Parenteral anticoagulants that are indirect thrombin/Xa inhibitors
Unfractionated/high molecular heparin
low molecular weight heparins:
-enoxaparin, dalteparin, tinzaparin
synthetic pentasccharides:
-fondaparinux
what are the paraenteral anticoagulants that are direct thrombin inhibitors
Bivalirudin
argatroban
what are the oral anticoagulant?
Coumarin derivative
Warfarin
what are the direct oral anticoagulant factor Xa inhibitors
rivaroxaban
apixaban
endoxaban
what are the direct oral anticoagulant thrombin inhibitors
dabigatran
what are the oral antiplatelet phosphodiesterase inhibitor?
dipyridamole, cilostazol
difference between a red clot and white clot
red clot is fibrin rich with trapped RBC
- atrial fibrillation to stroke
- DVT
- PE
White clot: platelet rich
-damaged endothelium ruptured atherosclerotic plaques that lead to unstable angina, myocardial infarction
what are some PAD complications?
Critical limb ischemia:
- sores that dont heal that lead to infection, tissue death (gangrene)
- may need amputation
Stroke and Heart attack
what is the best way for PAD prevention?
HEalthy lifestyle
- quit smoking
- keep diabetes under control
- exercise
- low cholesterol
- heat healthy foods and maintain a healthy weight
Medications to treat PAD
•
Cholesterol-lowering medications… e.g., statins (see “Drugs to Treat Hyperlipidemia”)
–
goal is LDL < 100 mg/dL
•
High blood pressure medications, if needed… (see “Drugs to Treat Hypertension and HTN Urgency/Emergency”)
–
goal is < 130/80 mm Hg
•
Control blood sugar levels if diabetic…
–
e.g., metformin for T2DM (drugs will be discussed in EN RE II, Med 218)
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Prevent arterial blood clots (see “Drugs to Treat Cardiac Arrhythmias/ACS/Stable Angina”)
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antiplatelet drugs: e.g., aspirin, clopidogrel… avoid concurrent gingko biloba (↑bleeding risk)
–
locally-infused clot buster drugs if occlusion from clot due to plaque rupture
•
Symptom-relief medications.
–
cilostazol
–
pentoxifylline, well-tolerated but less efficacious alternative
cilostazol MOA, effects and Clinical applications
MOA: type 3 phosphodiesterase inhibitor that prolongs life of cAMP on platelets and cells
Effects: Platelet aggregation inhibitor
-vasodilator
Clinical applications:
-intermittent claudication
Pharmacokinetics, toxicities and BB warning ciostazol
Pharmacokinetics:
- oral tablet 2x a day
- metabolized by CYP3A4
toxicities:
- headache
- diarrhea
- palpitations
- dizziness
- peripheral edema
BB warning: -contraindicated in patients with heart failure, use is asssociated with decreased survival of class III and class IV patients
what are the surgical treatment of PAD
Balloon or laser angioplasty stent
atherectomy
symptoms of an affected leg with DVT
swelling
pain and cramping in the calf
-red/discolored skin
-warmth
lead to PE
DVT risk factors
•
genetic blood-clotting disorder –e.g., factor V Leiden, mutation ↑prothrombin
•
prolonged bed rest, such as during a long hospital stay, or paralysis –calf muscles don’t help blood circulate
•
injury or surgical damage to veins
•
pregnancy
•
overweight or obese
•
oral contraceptives or hormone replacement therapy –estrogen ↑synthesis of clotting factors
•
smoking affects blood clotting and circulation
•
cancer –
•
vein compression by tumor, unusual blood flow patterns in tumor
•
hypercoagulable state due to secretions –e.g., tissue factor, ADP, thrombin, thrombogenic tumor exosomesdue to surface expression of phosphatidylserine
•
heart failure–low cardiac output means sluggish flow
•
inflammatory bowel disease–2-3x higher risk due to hypercoagulable state from altered expression of various proteins, exact etiology uncertain
•
family history
•
age… risk increases if age > 60 yrs
•
sitting for long periods of time, such as when driving or flying
DVT prevention
Avoid sitting still
-dont cross legs
Make lifestyle changes:
- lose weight if overweight
- quit smoking
Exercise
Drug options for treatment of DVT
Anticoagulants
Clot busters
Non-pharmacologic treatment of DVT
Compression socks
Stents
Vena cava filter
what drugs block white clot formation
antiplatelet drugs
what drugs block red clots formation
Anticoagulant drugs block thrombin activation/fibrin formation
what drugs destroy formed clots?
thrombolytic drugs
MOA effects and Clinical applications of heparin unfracetionated
MOA: made from lungs of cattle and pigs and lots can vary
- long polysaccharide chain
- pentasaccharide sequence found randomly that binds antithrombin III and inhibits factor Xa
effects:
- blocks generation of thrombin
- inactivates thrombin
- prevents red clots
Clinical applications:
-rapid onset anticoagulant effects
(PE, stroke, DVT, DIC, acute MI)
-used in pregnancy and doesn’t cross placenta
-used in catheters extracorporeal circuits
antidote: Protamine (positive charges)
Pharmacokinetics and toxicites
Pharma:
- parenterally (IV or SC) since it is negatively charged
- binds nonspecifically
- variable plasma levels so must monitor aPTT assay (1.5-2)
- half life 1.5 hrs can vary
Toxicities:
- contraindicted in thrombocytopenia and uncontrolled bleeding
- avoid in surgery
- heparin induced thrombocytopenia (reduced platelet and thrombotic events)
MOA, effects, and Clinical applications of Enoxaparin
MOA: LMW heparin
-cant form tertnary complex with antithrombin III and thrombin but factor Xa is inhibited
effects:
- selectively blocks factor Xa
- prevents red clots
- little effect on thrombin
Clinical applications:
- prevent DVT, after surgery
- treatment of DVT +/- PE
- prevent ischemic complications
- safe in pregnancy