THROMBOLYTIC DRUGS
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Transcript THROMBOLYTIC DRUGS
COAGULATION MODIFIER DRUGS
Lilley Reading and Workbook, Chap 27
COAGULATION MODIFIER DRUGS
Anticoagulants
Antiplatelet drugs
Inhibit platelet aggregation
Prevent platelet plugs
Thrombolytic drugs
Inhibit the action or formation of clotting factors
Prevent clot formation
Lyse (break down) existing clots
Hemostatic or Antifibrinolytic drugs
Promote blood coagulation
HEMOSTASIS
The process that halts bleeding after injury to a
blood vessel
Complex relationship between substances that
promote clot formation and either inhibit
coagulation or dissolve a formed clot
ANTICOAGULANTS
Have no direct effect on a blood clot that is
already formed
Used prophylactically to prevent
Clot formation (thrombus)
An embolus (dislodged clot)
COAGULATION SYSTEM
“Cascade”
Each activated factor serves as a catalyst that
amplifies the next reaction
Result is fibrin, a clot-forming substance
Intrinsic pathway and extrinsic pathway
ANTICOAGULANTS:
MECHANISM OF ACTION
Vary, depending on drug
Work on different points of the clotting cascade
Do not lyse existing clots
Heparin
& low-molecular-weight heparins enoxaparin (Lovenox)
Turn off coagulation pathway and prevent clot formation
Warfarin (Coumadin)
All ultimately prevent clot formation
ANTICOAGULANTS
Prevention of clot formation also prevents:
Stroke
Myocardial infarction (MI)
Deep vein thrombosis (DVT)
Pulmonary embolism (PE)
ANTICOAGULANTS: INDICATIONS
Used to prevent clot formation in certain
settings where clot formation is likely
Stroke
Atrial fibrillation
Myocardial infarction (MI) / Unstable Angina
Deep vein thrombosis (DVT)
Pulmonary embolism (PE)
Indwelling devices, such as mechanical heart valves
Major orthopedic surgery
ANTICOAGULANTS:
ADVERSE EFFECTS
Bleeding
Risk increases with increased dosages
May be localized or systemic
May also cause
Nausea, vomiting, abdominal cramps,
thrombocytopenia, others
ANTICOAGULANTS
Heparin
Monitored by activated partial thromboplastin
times (aPTTs)
Goal: Therapeutic range based on body weight based
dosage
aPTT between 1.5 – 2.5 times normal control level
Parenteral – IV bolus followed by infusion
Never mixed with any other medication
Short half-life (1 to 2 hours)
Effects reversed by protamine sulfate
Obtained from sheep, cows, and pigs
HEPARIN: NURSING IMPLICATIONS
Anticoagulant effects seen immediately
Laboratory values are done daily to monitor coagulation effects (aPTT)
Intravenous doses are usually double checked with another nurse
Ensure that SC doses are given SC, not IM
SC doses should be given in areas of deep subcutaneous fat, and sites
rotated
Bleeding precautions
ANTICOAGULANTS
Low-molecular-weight heparins
enoxaparin (Lovenox)
dalteparin (Fragmin)
More predictable anticoagulant response
Do not require frequent laboratory monitoring
Given subcutaneously – rotate sites
Patient may be instructed for home administration
Bleeding precautions
Protamine sulfate can be given as an antidote in case of
excessive anticoagulation
ANTICOAGULANTS
warfarin sodium (Coumadin)
Given orally only – usually late afternoon – same time daily
Monitored by INR (INR) - 2-4 depending on diagnosis
(Prothrombin time – lab-specific -- 1 ½ - 2 ½ times the control 12-15 sec)
Dose changed according to INR results
phytonadione (Vitamin K) can be given if toxicity occurs
WARFARIN - NURSING IMPLICATIONS
Assess:
Patient history, medication history, allergies
Contraindications
Baseline vital signs, laboratory values
Potential drug interactions—there are MANY!
History of abnormal bleeding conditions
Usually started 2-3 days prior to heparin infusion being
discontinued - until PT-INR levels indicate adequate
anticoagulation
Full therapeutic effect takes several days
Monitor PT-INR regularly—keep follow-up appointments
Antidote is phytonadione (Vitamin K)
WARFARIN -- NURSING IMPLICATIONS
Many herbal products have potential
interactions—increased bleeding may occur
Capsicum pepper
Garlic
Ginger
Gingko
Ginseng
Feverfew
ANTIPLATELET DRUGS
Indications
Antithrombotic effects
Reduce risk of fatal and nonfatal strokes
Adverse effects
Vary according to drug
ANTIPLATELET DRUGS
Prevent platelet adhesion
Aspirin
dipyridamole (Persantine)
clopidogrel (Plavix) and ticlopidine (Ticlid)
ADP inhibitors
tirofiban (Aggrastat), eptifibatide (Integrilin)
New class, GP IIb/IIIa inhibitors
ANTIPLATELET DRUGS:
NURSING IMPLICATIONS
Concerns and teaching tips
Same as for Anticoagulants
Dipyridamole should be taken on an empty stomach
Drug-drug interactions
Adverse reactions to report
Monitoring for abnormal bleeding
ANTIFIBRINOLYTIC DRUGS
Prevent the lysis of fibrin
Results: promote clot formation
Used for prevention and treatment of excessive
bleeding resulting from hyperfibrinolysis or
surgical complications
aminocaproic acid (Amicar)
desmopressin (DDAVP)
Similar to ADH
Also used in the treatment of diabetes insipidus
ANTIFIBRINOLYTIC DRUGS:
INDICATIONS
Prevention and treatment of excessive
bleeding
Hyperfibrinolysis
Surgical complications
Excessive oozing from surgical sites such as chest
tubes
Reducing total blood loss and duration of bleeding in
the postoperative period
ANTIFIBRINOLYTIC DRUGS:
ADVERSE EFFECTS
Uncommon and mild
Rare reports of thrombotic events
Others include:
Dysrhythmia, orthostatic hypotension, bradycardia,
headache, dizziness, fatigue, nausea, vomiting,
abdominal cramps, diarrhea, others
THROMBOLYTIC DRUGS
Drugs that break down, or lyse, preformed clots
Older drugs
streptokinase and urokinase
Newer drugs
Tissue plasminogen activator (TPA)
Anisoylated plasminogen-streptokinase
activator complex (APSAC)
THROMBOLYTIC DRUGS (CONT’D)
streptokinase (Streptase)
anistreplase (Eminase)
alteplase (t-PA, Activase)
reteplase (Retavase)
tenecteplase (TNKase)
drotrecogin alfa (Xigris)
THROMBOLYTIC DRUGS:
MECHANISM OF ACTION
Activate the fibrinolytic system to break down the
clot in the blood vessel quickly
Activate plasminogen and convert it to plasmin,
which can digest fibrin
Reestablish blood flow to the heart muscle via
coronary arteries, preventing tissue destruction
THROMBOLYTIC DRUGS:
INDICATIONS
Acute MI
Arterial thrombolysis
DVT
Occlusion of shunts or catheters
Pulmonary embolus
Acute ischemic stroke – Code Green
THROMBOLYTIC DRUGS:
ADVERSE EFFECTS
BLEEDING
Internal
Intracranial
Superficial
Other effects
Nausea, vomiting, hypotension, anaphylactoid reactions
Cardiac dysrhythmias
NURSING IMPLICATIONS
Assess:
Patient history, medication history, allergies
Contraindications
Baseline vital signs, laboratory values
Potential drug interactions—there are MANY!
History of abnormal bleeding conditions
THROMBOLYTIC DRUGS:
NURSING IMPLICATIONS
Follow strict manufacturer’s guidelines for
preparation and administration
Monitor IV sites for bleeding, redness, pain
Monitor for bleeding from gums, mucous
membranes, nose, injection sites
Observe for signs of internal bleeding (decreased
BP, restlessness, increased pulse)
ANTICOAGULANTS:
PATIENT EDUCATION
Education should include:
Importance of regular lab testing
Signs of abnormal bleeding
Measures to prevent bruising, bleeding, or tissue
injury
Wearing a medical alert bracelet
Avoiding foods high in vitamin K (tomatoes, dark
leafy green vegetables)
Consulting physician before taking other meds or
OTC products, including herbals
COAGULATION MODIFIER DRUGS
NURSING IMPLICATIONS
Monitor for therapeutic effects
Monitor for signs of excessive bleeding
Bleeding of gums while brushing teeth, unexplained
nosebleeds, heavier menstrual bleeding, bloody or tarry
stools, bloody urine or sputum, abdominal pain,
vomiting blood
Monitor for adverse effects
Increased BP, headache, hematoma formation,
hemorrhage, shortness of breath, chills, fever
REVIEW
Antiplatelet agents act by:
1. preventing extension of existing clots.
2. preventing platelets from uniting.
3. dissolving existing clots.
4. increasing blood viscosity.
REVIEW
Doses of heparin are based on what laboratory
report?
1. warfarin serum level
2. activated partial thromboplastin time
(APTT)
3. Lee White clotting time
4. prothrombin time (PT) and INR
REVIEW
Nursing responsibilities involved in the
administration of heparin subcutaneously
include:
1. checking calculations with a second
qualified nurse.
2. using a 20-gauge needle to inject the
drug.
3. injecting the drug deep intramuscularly
(IM).
4. aspirating before injecting the drug.
REVIEW
Clopidogrel (Plavix) is used to:
1. dissolve existing arterial blood clots.
2. prevent further movement of an embolus.
3. prevent platelet aggregation.
4. prevent extension of an existing
thrombus.