1. Agents Affecting Blood Clotting
Chapter 19
Agents Affecting Blood Clotting

2. Anticoagulants
Inhibit the action or formation of one or more clotting factors
Heparin-potent inhibitor of the clotting process
Used in the prophylaxis and treatment of clotting disorders

3. Anticoagulants Heparin
Indirectly interferes with the conversion of prothrombin to thrombin
The deficiency of thrombin prevents the conversion of fibrinogen to fibrin
Inhibits the formation of clots

4. Anticoagulants Heparin
Given subcutaneously of intravenously (continuous infusion)
Rapid and predictable action
First drug used in anticoagulant therapy
Patient changed to an oral anticoagulant when a desired prothrombin time is achieved

5. Anticoagulants Adverse effects subcutaneous bleeding
blood in the stool, hematuria
bleeding gums
nosebleeds
bruising
hypersensitivity

6. Anticoagulants Treatment of overdose 1% protamine sulfate
Inactivates heparin
Slow infusion

7. Anticoagulants
Many drug-drug and drug-herb interactions to heparin that increase bleeding and delay clotting time
Many drug-drug and drug-herb interactions that decrease the effect of heparin

8. Anticoagulants Lovenox Low molecular weight heparin anticoagulant
Only given subcutaneously
Prophylaxis and treatment of DVT

9. Anticoagulants Adverse effects bleeding gums nose bleeds bruising
hematuria
blood in stool

10. Oral Anticoagulants
Inhibits blood clotting by interfering with the synthesis of vitamin K-dependent clotting factors in the liver
Action is not evident for hours after the first dose

11. Oral Anticoagulants warfarin (Coumadin) More predictable action
lower incidence of adverse effects
Close monitoring of the patient
Dosages are individualized and dependant on INR

12. Oral Anticoagulants warfarin (Coumadin) therapeutic INR 2-3
Many drug-drug and drug-herb interactions
Overdosage: Vitamin K

13. Antiplatelet Agents clopidogrel (Plavix)
Inhibit the aggregation of platelets
Patients following a CVA or MI
May help prevent recurrence

14. Antiplatelet Agents
Patients should avoid using medications that contain aspirin
Avoid using non-steroidal anti-inflammatory drugs

15. Antiplatelet Agents clopidogrel (Plavix) Adverse effects dizziness
nose bleeds
GI bleeding
bleeding

16. Thrombolytic Agents Enzyme that dissolves fibrin clots
Indicated for the lysis of pulmonary emboli and for clearing clots from central venous catheters
streptokinase
urokinase

17. Thrombolytic Agents urokinase
Drug of choice for clearing central venous catheters
Patients should be monitored for bleeding