Pharm110 Chp 19 Anticoagulants, antiplatelets, Thrombolytics

Question 1

Anticoagulants

Answer 1

Heparin (subcut or IV)
Dalteparin, enoxaparin (low molecular weight, admind subcut)
Warfarin (oral)

• Prevent formation of a thrombus (blood clot)
• No direct effect on existing thrombus, do not reverse any damage from thrombus.
• Prevent additional clots from forming
• Commonly called blood thinners by patients

Question 2

Uses of anticoagulants

Answer 2

• Prophylaxis and treatment of DVT
• Prevent and treat atrial fibrillation with embolization
• Prevention and treatment of PE (pulmonary embolism)
• Adjuvent treatment of MI
• Prevent of postoperative DVT and PE in surgical patients.

Question 3

Anticoagulant warnings

Answer 3

Contraindicated in patients with

• Severe renal or hepatic disease
• Active bleeding
• GI ulcers
• Recent eye or CNS surgery
• Pregnancy(can cause fetal death) and lactation

Question 4

Anticoagulants Thrombolytic nursing implications

Answer 4

• Before administering first dose question patient about all drugs taken during the previous 2 to 3 weeks or if Pt. was recently hospitalized.
• If patient took any drugs, before admin, nurse notifies Dr.

Question 5

Heparin action

Answer 5

• Indirectly interferes with conversion of prothrombin to thrombin
• Deficiency of thrombin prevents the conversion of fibrinogen to fibrin, which prevents clot formation.
• Admin IV, do not give orally or IM
• Admin subcut (Longer acting form)
• No IM for risk of excessive bleeding

Question 6

Heparin admin do’s and don’ts

Answer 6

• Prefilled syringes, Do not expel air bubble
• Pinch fold in skin to for deep subcut admin
• 90 degree inject
• Do not aspirate
• Monitor aPTT (activated partial thromboplastin time) when admining heparin)
• Normal aPTT is 30-40 seconds (patients on heparin should have aPTT 1.5-2.5 times normal
• Contact Dr. if aPTT is not 1.5-2.5 times normal.

Question 7

Heparin adverse effects

Answer 7

-Hemorrhage
-Allergy
Antidote Protamine sulfate

Do not administer to clients with coagulation disorders e.g. hemophilia, Von Willebrand disease.

Question 8

Low Molecular weight heparins

Answer 8

Related to heparin
-Minor risk for bleeding
Does not affect action of thrombin in clotting cascade
Have little effect on the aPTT values

e.g. Enoxaparin, Dalteparin

Question 9

Warfarin

Answer 9

Only oral anticoagulant (used as rat poison)

• Inhibits blood clotting by interfering with the synthesis of vitamin K dependant clotting factors (II, VII, IX, and X) in the liver-The prothrombin time (PT) and international normalized ration (INR) is determined before therapy begins.
• The 1st dose of Warfarin is not given until the blood is drawn for baseline PT/INR test.
• Dosage is Individualized based on the results of the PT or the INR.
• Orals are most often used for long term therapy
• INR is maintained between 2 and 3
• The PT is kept between 25-30 seconds.

-Nurse withoholds drug and notifies Dr. if the INR exceeds the prescribed level or the PT exceeds 30 seconds.

Question 10

Bleeding risk

Answer 10

Bleeding can occur ANY time during Warfarin therapy, even with INR is within safe limits.

Warfarin overdose symptoms

• Blood in stool (melena)
• Petechiae (pin point sized red dots on skin)
• Bleeding gums after brushing teeth
• Bleeding cuts from shaving
• Excessive menstrual bleeding

Question 11

Warfarin nursing implications

Answer 11

Immediately report to Dr. any of the adverse effects or bleeding.

• Discontinue drug use for a few days or order Vitamin K (phytonadione) an oral anticoagulant antagonist.
• Vitamin K reverses Warfarin effects by providing necessary ingredient to enhance clot formation and stop bleeding.

Question 12

Warfarin patient and family teaching

Answer 12

• Keep all Dr and lab appointments
• Take drug at same time each day
• Avoid alcohol
• Maintain a consistent daily intake of vitamin K to help maintain a consistent INR value
• Avoid the use of aspirin and NDSAIDs
• Any evidence of bleeding notify Dr right away
• Use soft toothbrush and electric razor
• Women of childbearing age should use a reliable contraceptive to avoid pregnancy

Question 13

Antiplatelet agents

Answer 13

Inhibit the aggregation of platelets
-Treat patients who have had cerebrovascular accidents or myocardial infarctions

e.g. Acetylsalicylic acid (Aspirin)
Abciximab (ReoPro)
Clopidogrel bisulfate (Plavix)

Question 14

Thrombolytic agents

Answer 14

Enzymes that convert plasminogen to the enzyme fibrinolysin

• Only administered IV, they dissolve (lyse) potentially fatal blood clots.
• Given to pts. with AMI, ischemic stroke, pulmonary embolism, DVT.

e.g. Alteplase-recombinant (Activase)

Question 15

Thrombolytic for AMI

Answer 15

• Pt should receive drug within 12 hours after heart attack starts.
• Ideally pt. should receive drug within the first 90 minutes after arriving at the hospital
• Pt. may need PTCA or CABG even after administration

Question 16

Thrombolytic for Ischemic stroke

Answer 16

Pt. should receive thrombolytic within 3 hours of the first sign of stroke

• CT scan must be performed before drug is administered
• Never give to pt. with hemorrhagic stroke-it can worsen stroke and cause death.

Question 17

Thrombolytic adverse effects

Answer 17

• Major effect is bleeding. All IM injections MUST be avoided.
• Contraindicated in pts. with hemorrhagic stroke.
• Pts. who have had neurological procedures within 6 months.
• Pts. who have had major surgery or bleeding within 6 weeks.