1. Coagulation Modifier Drugs
Lilley Reading and Workbook, Chap 27

2. Coagulation Modifier Drugs
Anticoagulants
Inhibit the action or formation of clotting factors
Prevent clot formation
Antiplatelet drugs
Inhibit platelet aggregation
Prevent platelet plugs
Thrombolytic drugs
Lyse (break down) existing clots
Hemostatic or Antifibrinolytic drugs
Promote blood coagulation

3. 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

4. Anticoagulants
Have no direct effect on a blood clot that is already formed
Used prophylactically to prevent
Clot formation (thrombus)
An embolus (dislodged clot)

5. 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

8. 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

9. Anticoagulants Prevention of clot formation also prevents: Stroke
Myocardial infarction (MI)
Deep vein thrombosis (DVT)
Pulmonary embolism (PE)

10. 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

11. Anticoagulants: Adverse Effects
Bleeding
Risk increases with increased dosages
May be localized or systemic
May also cause
Nausea, vomiting, abdominal cramps, thrombocytopenia, others

12. 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

13. 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

14. 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

15. Anticoagulants warfarin sodium (Coumadin)
Given orally only – usually late afternoon – same time daily
Monitored by INR (INR) depending on diagnosis
(Prothrombin time – lab-specific -- 1 ½ - 2 ½ times the control sec)
Dose changed according to INR results
phytonadione (Vitamin K) can be given if toxicity occurs

16. 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)

17. Warfarin -- Nursing Implications
Many herbal products have potential interactions—increased bleeding may occur
Capsicum pepper
Garlic
Ginger
Gingko
Ginseng
Feverfew

18. Antiplatelet Drugs Indications Antithrombotic effects Adverse effects
Reduce risk of fatal and nonfatal strokes
Adverse effects
Vary according to drug

19. 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

22. 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

23. 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

24. 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

25. 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

26. 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)

27. Thrombolytic Drugs (cont’d)
streptokinase (Streptase)
anistreplase (Eminase)
alteplase (t-PA, Activase)
reteplase (Retavase)
tenecteplase (TNKase)
drotrecogin alfa (Xigris)

28. 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

29. Thrombolytic Drugs: Indications
Acute MI
Arterial thrombolysis
DVT
Occlusion of shunts or catheters
Pulmonary embolus
Acute ischemic stroke – Code Green

30. Thrombolytic Drugs: Adverse Effects
BLEEDING
Internal
Intracranial
Superficial
Other effects
Nausea, vomiting, hypotension, anaphylactoid reactions
Cardiac dysrhythmias

31. 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

32. 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)

33. 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

34. 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

35. Review
Antiplatelet agents act by: 1. preventing extension of existing clots. 2. preventing platelets from uniting. 3. dissolving existing clots. 4. increasing blood viscosity.

36. 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

37. 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.

38. 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.