Drugs affecting blood coagulation chapter 48 Flashcards
What are drugs that are affecting blood coagulation?
- Antiplatelet Drugs
- Anticoagulation Drugs
- Thrombolytic Drugs
- Hemostatic Drugs
- Drugs to Control Bleeding
Describe anti platelet drug?
- Antiplatelet drugs inhibit platelet aggregation and adhesion
- Decrease responsiveness of stimuli that cause plt to aggregate on vessel wall
What are indications of anti platelet drugs?
- CAD – prone to occluded vessels
- Maintenance of arterial/venous grafts
- Prevent cerebrovascular occlusion
- During/post MI for thrombolytic effect
whats aspirin?
Antiplatelet drug
What are therapeutic actions of asprin?
Antiplatelet drug
Inhibits synthesis of thromboxane A2
* Decreases plt aggregation
What are adverse affects of aspirin
Anti platelet drug
- Bleeding
- CNS –> HA dizziness, weakness
- Monitor for salicylate poisoning
What are contras of aspirin?
Anti platelet drug
- Bleeding disorder
- Uncontrolled HTN
- Recent/impending surgery
What are drug to drug interaction with aspirin?
Increase risk of bleeding when
combined with other
anticoag/antiplatelet drugs
Describe anticoagulation?
- All anticoagulants work in clotting cascade
but do so at different points - Prevent formation of new clots and
extension of clots already present - Do not dissolve clots
- Heparin and warfarin are commonly used
- Used to prevent or manage
thrombophlebitis, deep vein thrombosis
(DVT), and pulmonary emboli (PE) - Main adverse effect is bleeding
What is heparin?
Anticoagulants
What is the therapeutic action of heparin?
Anticoagulants
* Interfere with normal coagulation by disrupting normal clotting cascade
* Blocks formation of thrombin from prothrombin
What are indications of heparin ?
Anticoagulants
- Acute clinical situations
- DVT prevention
- Prevention of clotting in blood samples/dialysis tubing
- NOT used in routine IV locks
- Drug of choice in pregnancy – if necessary
What are pharmacokinetics of heparin ?
Anticoagulants
SC
* Onset within 20-60 minutes
IV Administration
* IVP rapid action
IV continuous
* Weight based ordering
* Monitor PTT every 6 hours until stabilized and on
maintenance dose
What are contras for heparin?
Anticoagulants
Active bleeding – hemorrhagic disorders, trauma, spinal taps, GI ulcers
What are cautions of heparin?
Anticoagulants
* Thrombocytopenia
* HIT – drop in platelets approx. 30-50% from baseline
(Heparin induced thrombocypenia)
could cause platelets to clot in presence in heparin
What to monitor for the therapeutic response heparin?
-PTT (60-80 most common range)
Partial thromboplastin; How long it takes your blood to clot
* aPTT (1.5 – 2.5 x control value)
What is heparin antidote?
protamine sulfate
How is warafin given?
Most commonly used oral anticoagulant
what are therapeutic actions of warfarin (Coumadin)?
Anticoagulant
Prevents synthesis of vitamin K by bacteria in the GI tract
* This inhibits production of clotting factors II, VII, IX and X– known as the Vit K dependent factors
INR (nl < 1.1) determined by dx (2-3 most common range. Person on warfarin should be at 2-3
What are indications with warfarin?
Anticoagulant
** Prevention or management of DVT, PE and embolization associated with atrial fibrillation and
prosthetic heart valves
What are pharmacokinetics of Warfarin?
Anticoagulant
Anticoagulant effects occur 2-5 days after oral use
What are contras/cautions with warafin?
Anticogulant
* Pregnancy, renal/hepatic dz, all others as per heparin
What are drug to drug interactions with warafin?
Anticoagulant
MANY!! (ex: increased coag effect with PCN; decreased coag effect with digoxin)
Food high in Vit K
What is antidote for warfarin?
Anticoagulant
Antidote – phytonadione (vitamin K)
* PO, SQ, IVPB (beware)
What is dabigatran etexilate mesylate (Pradaxa)?
Anticoagulant
What is therapeutic action of dabigatran etexilate mesylate (Pradaxa)?
Anticoagulant
Acts by inhibiting thrombin
What are indications of dabigatran etexilate mesylate (Pradaxa)?
Anticoagulant
Indicated for atrial fibrillation (not caused by
valve problems) to prevent stroke
What are contras/ cautions of dabigatran etexilate mesylate (Pradaxa)?
same as warfarin and heparin
Contras:
* Active bleeding – hemorrhagic disorders, trauma, spinal taps, GI ulcers
* Cautions:
* Thrombocytopenia
* HIT – drop in platelets approx. 30-50% from baseline
difference between dabigatran etexilate mesylate (Pradaxa) and older drugs?
Antocoag
Benefits over older coags:
* Does not require frequent lab follow-up
* Low potential for drug-drug interactions
* No drug-food interactions
What are concerns with dabigatran etexilate mesylate (Pradaxa)
Anticoag
* Bleeding episodes more serious
Antidote – idarucizumab (Praxbind)
ANTICOAGULANTS: DABIGATRAN
What is enoxaparin (Lovenox)?
ANTICOAGULANTS: LOW-MOLECULAR-
WEIGHT HEPARINS (LMWH)
What a therapeutic actions of enoxaparin (Lovenox)?
Low molecular weight heparins
Synthetic – inhibits thrombus/clots by binding to factors Xa and II
What are benefits of enoxaparin (Lovenox)?
Low molecular weight heparins
More predictable response
* No intense monitoring of blood required
* Prevention or management of thromboembolic disorders
* Less thrombocytopenia than heparin
What are indications enoxaparin (Lovenox)?
Low molecular weight heparins
Often used for bridge therapy with warfarin
What are antidotes for enoxaparin (Lovenox)?
Low molecular weight heparins
Antidote: protamine sulfate (?)
What is contra for enoxaparin (Lovenox)?
Low molecular weight heparins
- Contra: epidural catheters
What is lepirudin (Refludan)?
Anticoag- Heparin/LMWH alternatives
What is therapeutic action of lepirudin (Refludan)?
Anticoag- Heparin/LMWH alternatives
Inhibits thrombin – similar to heparin mechanism
What are indications for lepirudin (Refludan)??
Anticoag- Heparin/LMWH alternatives
- Allergy to heparin
- Pts at risk for HIT or with a documented history
What are pharmacokinetics of lepirudin (Refludan)?
Anticoag- Heparin/LMWH alternatives
- PTT followed for therapeutic effect
- IV route only (continuous infusion)
What are nursing considerations with lepirudin (Refludan)?
- Soft toothbrush
- Electric razor
- No IM shots
- Hold veni puncture sites
- Monitor for bleeding, bruising
- When/what to report
- Dietary restrictions (warfarin)
- Let PCP know of other meds/ herb/
vitamins - No contact sports
- Note allergy – consider for ALL
heparin products - Medical alert bracelet
- Avoid OTC drugs –addition of
other drugs
Describe THROMBOLYTIC AGENTS
Dissolve thrombi
* Stimulate conversion of plasminogen to plasmin – breaks fibrin clot
* Goal is to reestablish blood flow and prevent or limit tissue damage
What are indications of thrombolytic agents?
- Indications:
- Management of acute, severe thromboembolic disease such as MI, PE
- Dissolve clots in arterial or venous catheters
What is alteplase (Activase)
thrombolytic agents
tissue plasminogen
activator (t-PA)
-Fibrin specific – work
specifically at the site of the
clot
* Lower risk of systemic
thrombolysis than earlier drugs
What are contras of alteplase (Activase)
thrombolytic agents
tissue plasminogen
activator (t-PA)
- Recent surgery
- Active bleeding
- CVA within last two months
- Uncontrolled HTN
- Pregnancy
What are cautions with alteplase (Activase)
thrombolytic agents
tissue plasminogen
activator (t-PA)
- Monitor for bleeding
- Cardiac reperfusion syndrome
- Hypersensitivity – flushing, bronchospasm
What is **aminocaproic acid (Amicar)? And what is the therapeutic action
Hemostatic agent
- Therapeutic actions:
- Stop excessive bleeding –>prevents the lysis/breakdown of clots
What are indications aminocaproic acid (Amicar)?
Hemostatic angents/help control bleeding
* Indications:
* Used in surgery (IV), wound care (gel form/sponge), subarachnoid hemorrhage
What are contras aminocaproic acid (Amicar)?
Hemostatic agents/help control bleeding
- Allergy, pregnancy
- Cautions:
- Renal/hepatic disease, monitor for excessive clotting
What are cautions aminocaproic acid (Amicar)?
Hemostatic agents/help control bleeding
* Renal/hepatic disease, monitor for excessive clotting
HEMOSTATIC AGENTS
What is therapeutic action and indications of Antihemophilic factor- (Factor VIII)
Help control bleeding:
* Replacement factors for the specific clotting factors patient is missing/low
* Factors VIII, VIIa, IX
What are Pharmacokinetics of Antihemophilic factor- (Factor VIII)
control bleeding
- Given IV
What are adverse effects of Antihemophilic factor- (Factor VIII)
control bleeding
- HA, flushing, fevers, chills
What are contras of Antihemophilic factor- (Factor VIII)
control bleeding
* Allergy to mouse/bovine proteins
* Pregnancy/ lactation
