Immunity and coagulation 4 Flashcards
Anticoagulant Medications
group of medications that decrease clotting
Heparin & Low Molecular Weight Heparins (LMWH) examples
Enoxaparin(Clexane)
Dalteparin (Fragmin)
Heparin & Low Molecular Weight Heparins (LMWH) mechanism action
Acts by increasing function of antithrombin III which inhibits factor IXa, Xa, Xia & XIIa
Given parenterally only (usually IV or S/C)
Uses:Heparin & Low Molecular Weight Heparins (LMWH)
Prophylaxis: to prevent thromboembolism in high risk clients
Pulmonary embolism (PE) and deep venous thrombosis (DVT)
Prevent coagulation in heart-lung machine in open heart surgery
Prosthetic heart valves, haemodialysis
Adverse Effects: :Heparin & Low Molecular Weight Heparins (LMWH)
Most common: Haemorrhage Manifested by such symptoms as nose bleeds, black stools, bruising from unknown cause, bleeding gums
Less common effects: osteoporosis, alopecia, thrombocytopenia
Antidote:
Heparin and LMWH
Protamine sulphate (prepared from salmon sperm) is effective heparin antagonist if administered slowly. Fast administration can lead to anaphylaxis. Close monitoring of blood coagulation tests is required
Heparin and LMWH
Clinical Considerations:
Initiation of anticoagulant therapy can involve commencing heparin (SC/IV) and warfarin (oral) together then heparin can be ceased
While patient is receiving heparin therapy, the activated partial thromboplastin time (aPTT) must be monitored
Heparin is high-molecular-weight which can cause thrombocytopenia
Low-molecular-weight alternatives do not have these side effects of bleeding.
Warfarin example
, Coumadin and Marevan
Mechanism of action:
warfarin
Structurally similar to vitamin K
Vitamin K is involved in synthesis of prothrombin and factors II, VII, IX and X
Warfarin interrupts effect of vitamin K and depletes stores of vitamin K in liver
Takes several days to exert its effect
Uses:warfarin
Long term anticoagulation therapy
Administered orally
Similar to heparin
Adverse effects:
warfarin
Bleeding if not monitored closely
Less common effects: alopecia
Warfarin antidote
Vitamin K is a useful antagonist to warfarin eg. in cases of bleeding
Client Education:
Take medication at same time every day
Keep an anticoagulation book to document doses
Client to notify doctor if any signs of bleeding
Limit foods that are high in vitamin K
Eg. Green leafy vegetables such as cabbage
Non-vitamin K Oral Anti Coagulants(NOACs)
Direct Thrombin inhibitor
Direct Factor Xa inhibitor
Direct Thrombin inhibitor
. Dabigatran (
Direct Factor Xa inhibitor
Rivaroxaban, Apixaban, Edoxaban
Options for reversal: Prothombincomplex concentrate (PCC), Recombinant Factor VIIa (rFVIIa), activated PCC
Uses: Non-vitamin K Oral Anti Coagulants(NOACs)
Prevention of stroke in AF
Treatment of venous thromboembolism
Thromboprophylaxis after elective hip and knee surgery
As effective as warfarin, no need for INR
Thrombolytic (fibrinolytic) Drugs:
mechanism of action
Use:
Streptokinase
Potent plasminogen activator (which digests or dissolves fibrin clots)
Dissolves clots (PE, DVT, other clots
Adverse effects:
Clinical considerations:
Will dissolve clots formed from normal anticoagulation activity such as wound from injection
Uncontrolled haemorrhage
Allergic reaction, ie. anaphylaxis
Fever
Discontinue heparin before using streptokinase
Treatment likely to be ineffective if client has received streptokinase therapy within last 12 months or after severe streptococcal infection (ie. rheumatic fever)
-Antiplatelet Drugs -
Mechanism of action
uses
Aspirin
Stops platelet activity, renders platelets ineffective
Use: Angina, acute myocardial infarction, post cardiac bypass surgery, reduction of strokes (CVA)
Adverse reactions:
Clinical considerations:
Gastrointestinal problems
Allergic reaction (mainly to salicylates)
Clinical considerations:
Adjunct in thrombolytic therapy
Anticoagulant prophylaxis
Cease aspirin 1 week before surgery/dental procedures
Keep tablets in packaging until immediately before use (unless enteric coated)
Clopidogrel
Use
examples
Inhibits platelet aggregation
Inhibits platelet aggregation
Prevention of thromboembolic strokes in clients who are high risk, ischaemic heart disease
Adverse reactions
Clinical considerations
clopidogrel
Possible neutropenia
Similar to aspirin minus gastrointestinal effects and no salicylate side effects
Monitor FBC
Do not administer with other anticoagulants
Monitor for signs of bleeding
