Anticoagulants Flashcards
Anticoagulants/Parenteral
1) Heparin Sodium
- parenteral anticoagulants prevent bleeding by inactivation of thrombin formation and factor X, resulting in the inhibition of the formation of fibrin
2) low molecular weight heparins
- enoxaparin (Lovenox)
Anticoagulants/Parenteral: Uses
1) for conditions necessitating prompt anticoagulant activity (stroke, PE, massive DVT)
2) during pregnancy
3) as an adjunct for clients having open heart surgery or dialysis
4) in conjunction with thrombolytic therapy when treating acute MI
Anticoagulants/Parenteral: nursing interventions
1) monitor CBC, platelet count, and Hct levels
2) for continuous IV administration, use IV pump and monitor rate of infusion every 30-60 min
3) monitor aPPT every 4-6 hr until appropriate dose is determined. Then, monitor daily
4) Lovenox does not require frequent laboratory monitoring
5) half life is 2-3 times longer than heparin
Effectiveness of medication
- aPTT levels of 60-80 seconds (1.5-2.5 times the normal value of 30-36 seconds)
- no development or further development of venous thrombi
Antidote
- protamine sulfate treats heparin overdose
- it binds with heparin and forms a heparin-protamine complex that has no anticoagulant properties
- administer protamine sulfate slowly through an IV, no faster than 50 mg in 10 min
Anticoagulant/Oral
- prototype = warfarin (Coumadin)
- oral anticoagulants antagonize vitamin K, thereby preventing the synthesis of four coagulant factors: factors VII, IX, X, and prothrombin
Anticoagulant/Oral: uses
oral anticoagulants prevent:
1) venous thrombosis
2) thrombus formation in clients with atrial fibrillation
3) thrombus formation in clients with prosthetic heart valve
Anticoagulant/Oral: contraindications
-oral anticoagulants fall in pregnancy risk category X due to their high risk of fetal hemorrhage, fetal death, and CNS defects. advise client to notify the provider if she becomes pregnant while taking warfarin. if anticoagulation is needed during pregnancy, use heparin.
Anticoagulant/Oral: nursing interventions
1) monitor PT (therapeutic level 18-24 seconds) and INR levels (therapeutic levels 2-3). INR levels are most accurate. hold the dose and notify the PCP if these levels exceed therapeutic ranges
2) clients DO NOT experience anticoagulant effects from warfarin for 8-12 hours with full therapeutic effect being achieved in 3-5 days. clients will need to continue heparin infusion when they start taking oral warfarin
3) clients should avoid alcohol, OTC and nonprescription medications to prevent medication interactions
4) advise client to avoid sitting for prolonged periods of time and wearing tight-constricting clothing. client will need to elevate and move the legs wen sitting to avoid development of thrombi
5) advise the client to wear a medical alert bracelet that indicates they take warfarin
6) teach client to self-monitor PT and INR at home as appropriate
Anticoagulant/Oral: client education
1) avoid concurrent use of aspirin or glucocorticoids
2) supply client with list of foods high in vitamin K, as these foods can decrease anticoagulant effects when consumed in excessive amounts (dark green leafy vegetables, cabbage, cauliflower, soybeans)
3) clients should be educated about observing for bleeding gums, blood in urine or vomit, blood in stool, or petechiae
4) clients should know about methods for preventing bleeding (using an electric razor for shaving, brushing teeth gently)
Anticoagulant/Oral: medication effectiveness
- PT 1.5-2 times control (normal PT is 9.6-11.8 seconds)
- INR of 2-3 (normal INR is 1.3-2.0)
- no development, or no further development of venous thrombi
Anticoagulant/Oral: Antidote
- vitamin K = antidote
- it promotes synthesis of coagulation factors VII, IX, X, and prothrombin
- administer small doses of vitamin K (2.5 mg by mouth, 0.5-1 mg IV) to prevent development of resistance to warfarin
