Pharmacology Exam 2 - Everything on the test was exactly in
these notes
,Chp 26
Hemostasis
- The stopping of a flow of blood
- Coagulation is hemostasis that occurs because of the physiologic clotting of blood
- Thrombus: Blood clot (stationary)
- Embolus: thrombus that moves through blood vessels.
Coagulation System
- The Liver is responsible for the clotting cascade.
o The liver activates prothrombin, then it turns into a thrombin, which then turn
into fibrinogen and then becomes fibrin which forms a mesh that attracts the
platelets and stop the bleeding.
Fibrinolytic System
- Initiates the breakdown of clots and serves to balance the clotting process
- Fibrinolysis
o mechanism by which formed thrombi are lysed (destroyed) to prevent excessive
clot formation and blood vessel blockage
Hemophilia
- Rare genetic disorder
- Lacks certain clotting factors.
- Patients with hemophilia can bleed to death if coagulation factors are not given.
Coagulation Modifier Drugs
- Anticoagulants
o Prevents clot formation
o It does not dissolve clots and it doesn’t have any action on platelets
- Antiplatelet drugs
o Inhibit platelet aggregation (clumping together of platelets)
o Prevent platelet plug
▪ Ex: Aspirin
- Thrombolytic drugs
o Lyse (break down) existing clots
Anticoagulants
- Also known as antithrombotic
- Can be used prophylactically to prevent clots
- Does not help with a blood clot that is already formed
- Prevent intravascular thrombosis by decreasing blood coagulability
- Used prophylactically to prevent
o Clot formation (thrombus)
o An embolus (dislodged clot)
,Embolus
- Thromboembolic events
o Myocardial infarction (MI): embolus lodges in a coronary artery
o Stroke: embolus obstructs a brain vessel
o Pulmonary emboli: embolus in the pulmonary circulation
o Deep vein thrombosis (DVT): embolus goes to a vein in the leg
Anticoagulants Drugs (KNOW THIS)
- Heparins-part 1
o Given prophylactically to prevent clots
- Low-molecular- weight heparins (LMWH)
o Enoxaparin (Lovenox)
▪ A subcutaneous heparin given prophylactically to prevent clots.
▪ This Is only given Sub q
▪ No lab valued to be monitored.
o Dalteparin (Fragmin)
- Heparins- part 2
o Un-fractioned heparin (given IV only)
▪ This is NOT prophylactic, this is for someone who has a thromboembolic
event.
▪ Patient usually get this on IV drip or a bolus
o Must monitor PTT lab value when someone is on IV heparin.
Warfarin (Coumadin)
- Comes PO only
- Mechanical heart valve
- Most commonly prescribed oral anticoagulant
- Careful monitoring of the prothrombin time/international normalized ratio (PT/INR)
- A normal INR (without warfarin) is 1.0, but a therapeutic INR (with warfarin) ranges
from 2 to 3.0, (3.0-3.5 mechanical valve) depending on the indication for use of the
drug (e.g., atrial fibrillation, thromboprevention, prosthetic heart valve).
- Many drug interactions
- Dietary considerations: Green leafy vegetables (Don’t eat too much)
Nursing Implications Warfarin (Coumadin)
- May be started while the patient is still on heparin until PT/INR levels indicate adequate
anticoagulation
- Full therapeutic effect takes several days.
- Monitor PT/INR regularly; keep follow-up appointments.
- Antidote is vitamin K.
Treatment: Toxic Effects of Warfarin (KNOW THIS)
, - Discontinue the warfarin.
- May take 36 to 42 hours before the liver can resynthesize enough clotting factors to
reverse the warfarin effects
- Vitamin K1 (phytonadione)-antidote to warfarin- can hasten the return to normal
coagulation.
- High doses of vitamin K (10 mg) given IV will reverse the anticoagulation within 6
hours.
- Many herbal products have potential interactions; increased bleeding may occur
o Capsicum pepper
o Garlic
o Ginger
o Ginkgo
o St. John’s wort
o Feverfew
Enoxaparin (Lovenox)
- Prototypical LMWH
- Greater affinity for factor Xa than for factor Iia
- Higher degree of bioavailability and longer elimination half-life
- Lab monitoring is not necessary.
- Injectable form
- Used for prophylaxis and treatment
- Pre-filled syringes
- Do not expel air bubble
Nursing Implications for LWMH
- Given subcutaneously in the abdomen
- Rotate injection sites.
- Protamine sulfate can be given as an antidote in case of excessive anticoagulation, but
rarely
Heparin
- Natural anticoagulant obtained from the lungs or intestinal mucosa of pigs
- 10 to 40,000 units/mL
- DVT prophylaxis: 5000 units subcutaneously two or three times a day; does not need to
be monitored when used for prophylaxis
- When heparin is used therapeutically (for treatment), continuous IV infusion.
o Measurement of aPTT (usually every 4-8 hours until therapeutic effects are
seen) is necessary
Nursing Implications for Heparin
- IV doses are usually double checked with another nurse.
these notes
,Chp 26
Hemostasis
- The stopping of a flow of blood
- Coagulation is hemostasis that occurs because of the physiologic clotting of blood
- Thrombus: Blood clot (stationary)
- Embolus: thrombus that moves through blood vessels.
Coagulation System
- The Liver is responsible for the clotting cascade.
o The liver activates prothrombin, then it turns into a thrombin, which then turn
into fibrinogen and then becomes fibrin which forms a mesh that attracts the
platelets and stop the bleeding.
Fibrinolytic System
- Initiates the breakdown of clots and serves to balance the clotting process
- Fibrinolysis
o mechanism by which formed thrombi are lysed (destroyed) to prevent excessive
clot formation and blood vessel blockage
Hemophilia
- Rare genetic disorder
- Lacks certain clotting factors.
- Patients with hemophilia can bleed to death if coagulation factors are not given.
Coagulation Modifier Drugs
- Anticoagulants
o Prevents clot formation
o It does not dissolve clots and it doesn’t have any action on platelets
- Antiplatelet drugs
o Inhibit platelet aggregation (clumping together of platelets)
o Prevent platelet plug
▪ Ex: Aspirin
- Thrombolytic drugs
o Lyse (break down) existing clots
Anticoagulants
- Also known as antithrombotic
- Can be used prophylactically to prevent clots
- Does not help with a blood clot that is already formed
- Prevent intravascular thrombosis by decreasing blood coagulability
- Used prophylactically to prevent
o Clot formation (thrombus)
o An embolus (dislodged clot)
,Embolus
- Thromboembolic events
o Myocardial infarction (MI): embolus lodges in a coronary artery
o Stroke: embolus obstructs a brain vessel
o Pulmonary emboli: embolus in the pulmonary circulation
o Deep vein thrombosis (DVT): embolus goes to a vein in the leg
Anticoagulants Drugs (KNOW THIS)
- Heparins-part 1
o Given prophylactically to prevent clots
- Low-molecular- weight heparins (LMWH)
o Enoxaparin (Lovenox)
▪ A subcutaneous heparin given prophylactically to prevent clots.
▪ This Is only given Sub q
▪ No lab valued to be monitored.
o Dalteparin (Fragmin)
- Heparins- part 2
o Un-fractioned heparin (given IV only)
▪ This is NOT prophylactic, this is for someone who has a thromboembolic
event.
▪ Patient usually get this on IV drip or a bolus
o Must monitor PTT lab value when someone is on IV heparin.
Warfarin (Coumadin)
- Comes PO only
- Mechanical heart valve
- Most commonly prescribed oral anticoagulant
- Careful monitoring of the prothrombin time/international normalized ratio (PT/INR)
- A normal INR (without warfarin) is 1.0, but a therapeutic INR (with warfarin) ranges
from 2 to 3.0, (3.0-3.5 mechanical valve) depending on the indication for use of the
drug (e.g., atrial fibrillation, thromboprevention, prosthetic heart valve).
- Many drug interactions
- Dietary considerations: Green leafy vegetables (Don’t eat too much)
Nursing Implications Warfarin (Coumadin)
- May be started while the patient is still on heparin until PT/INR levels indicate adequate
anticoagulation
- Full therapeutic effect takes several days.
- Monitor PT/INR regularly; keep follow-up appointments.
- Antidote is vitamin K.
Treatment: Toxic Effects of Warfarin (KNOW THIS)
, - Discontinue the warfarin.
- May take 36 to 42 hours before the liver can resynthesize enough clotting factors to
reverse the warfarin effects
- Vitamin K1 (phytonadione)-antidote to warfarin- can hasten the return to normal
coagulation.
- High doses of vitamin K (10 mg) given IV will reverse the anticoagulation within 6
hours.
- Many herbal products have potential interactions; increased bleeding may occur
o Capsicum pepper
o Garlic
o Ginger
o Ginkgo
o St. John’s wort
o Feverfew
Enoxaparin (Lovenox)
- Prototypical LMWH
- Greater affinity for factor Xa than for factor Iia
- Higher degree of bioavailability and longer elimination half-life
- Lab monitoring is not necessary.
- Injectable form
- Used for prophylaxis and treatment
- Pre-filled syringes
- Do not expel air bubble
Nursing Implications for LWMH
- Given subcutaneously in the abdomen
- Rotate injection sites.
- Protamine sulfate can be given as an antidote in case of excessive anticoagulation, but
rarely
Heparin
- Natural anticoagulant obtained from the lungs or intestinal mucosa of pigs
- 10 to 40,000 units/mL
- DVT prophylaxis: 5000 units subcutaneously two or three times a day; does not need to
be monitored when used for prophylaxis
- When heparin is used therapeutically (for treatment), continuous IV infusion.
o Measurement of aPTT (usually every 4-8 hours until therapeutic effects are
seen) is necessary
Nursing Implications for Heparin
- IV doses are usually double checked with another nurse.
