Anticoagulants Deck 3 Flashcards
Heparins clinical use and dosing
◦ Given 2 hours pre-operatively
◦ Maintenance every 8 to 12 hours for 7 days after surgery
LMWH clincial use and dosing
◦ Enoxaparin ◦ DVT or PE ◦ Given 2 hours before surgery ◦ Fondaparinux ◦ DVT ◦ Hip fracture surgery or knee replacement ◦ Dalteparin ◦ Prevention of DVT after abdominal surgery or hip replacement
Heprins each visit
◦ Lab*, History: side effects, injuries, lifestyle changes, med rec; PE: signs and symptoms of increased/decreased
INR
Heprins administration
◦ Warfarin dosing may vary day to day
◦ SC administration instruction for LMWH at home
Heprins ADR
◦ Risk for bleeding
◦ Vitamin K–containing foods
◦ Monitor for signs and symptoms
Heperains monitoring
◦ More frequent INRs in beginning until stable and therapeutic 24h with warfarin
◦ Protamine Sulfate is antidote for heparin OD
Antiplatelets: work
to prevent platelet adhesion at the site of injury before the coagulation cascade
Aspirin MOA
◦ Inhibits cyclooxygenase ◦ Interferes with platelet aggregation
◦ Ticlopidine and clopidogrel MOA
◦ Reduces platelet aggregation by inhibiting adenosine diphosphate pathway
◦ Vorapaxar MOA
◦ Protease-activated receptor-1 antagonist ◦ Inhibits thrombin-induced and thrombin receptor agonist peptide-induced platelet aggregation
◦ Taken with aspirin or clopidrogrel thrombin receptor agonist peptide induced platelet aggregation
THROMPIN RECEPTOR ANTAGONIST
Aspirin Pharmacokinetics
◦ Well absorbed when taken orally
◦ Metabolized in liver ◦ Renally excreted (pH affects excretion)
Ticlopidine Pharmacokinetics
◦ Rapidly absorbed after oral administration
◦ Metabolized in liver ◦ Non-linear PK: Half-life lengthens with repeated dosing
◦ Decreased renal clearance with age
Clopidogrel Pharmacokinetics
◦ Prodrug: metabolized into active metabolite
◦ Excreted in urine and feces
Ticagrelor is heavily
Heavily metabolized in liver
Vorapaxar pharmacokientics
◦ Metabolized by CYP3A4 and CYP2J2
◦ Half-life is 8 days
ASA clinical use and dosing
◦ Myocardial infarction (MI) prevention low risk: 75 to 100 mg daily ◦ Persistent atrial fibrillation: 75 to 325 mg daily ◦ Stroke or TIAs: 50 to 100 mg daily
Clopidogrel Clinical Use and Dosing
◦ MI prevention with history: 75 mg daily
◦ ST-elevation acute coronary syndrome: 300 mg daily if younger than 75 years of age and 75 mg daily if older than 75 years of age
Ticlopidine Clincial Use and Dosine
◦ Prevents strokes in patients intolerant of acetylsalicylic acid: 250 mg twice daily
Ticaragelor clinical use and dosing
◦ MI prevention (acute coronary symptoms): 90mg bid Plus low dose ASA
ASA precautions
◦ Hypersensitivity ◦ Cross-sensitivity with nonsteroidal antiinflammatory drugs (NSAIDs) ◦ Pregnancy category C (D in thir
Clopidogrel and ticlopidine precautions
◦ Avoid in patients with liver dysfunction
◦ Category B, but use only if clearly indicated
Vorapaxar black box
warning not to use in patients with history of stroke or transient ischemic attack (TIA)
ADR for ASA
◦ May cause gastrointestinal (GI) bleeding
◦ Salicylism (tinnitus) ◦ Potential for cross-sensitivity to NSAIDs
ADR triclopidine ADR
◦ HIGH RISK* for life-threatening hematological adverse reactions including neutropenia, agranulocytosis, and thrombotic thrombocytopenic purpura (TTP) ◦ 50% experience GI side effects
◦ Increases lipid levels
Ticagrelor black box
Black Box warning: no use if active bleeding, history intracranial hemorrhage
Vorapaxar black box
◦ Black Box warning: no use if active bleeding, history CVA, intracranial hemorrhage
general antiplatelet interacions
Concurrent use of other antiplatelet, anticoagulant, or fibrinolytic drugs, dipyridamole, quinidine, valproic acid
asa INTERACIONS
rin
◦ Herbals (gingko, garlic, ginseng) ◦ NSAIDs
clopidogrel interaconts
◦ Proton pump inhibitors (PPIs) ◦ CYP2C19 inhibitors
ticlopidine interancions
◦ Antacids
◦ Digoxin
◦ Cimetidine
ticargrelor interactions
◦ CYP3A4 inhibitors and inducers
vorapaxar interaciosn
◦ Combined with aspirin or clopidogrel to prevent thrombotic cardiovascular (CV) events
Take aspirin, ticlodipine with a
full glass of water
Consider enteric coated
aspirin (cannot be crushed or chewed)
Aspirin must be stopped
7 days before surgery
Clopidogrel should not be taken with
PPIs (over-the-counter Prilosec or omeprazole)
Ticragrelor should be stopped
5 days before surgery
Take steps to minimize bleeding:
soft toothbrushes, avoid flossing, shaving. ◦ Apply pressure 5-10 minutes if cut
