Anticoagulants (warfarin; heparin)

Selective Xa Inhibitors Which of these medications is an oral selective Xa inhibitor that is used for prevention of strokes in patients with atrial fibrillation (a-fib)? fondaparinux sodium enoxaparin rivaroxaban apixapan

Rivaroxaban is the first oral Xa inhibitor to become available and is used for the prevention of strokes in patients with atrial fibrillation (a-fib), for post-op thromboprophylaxis with ortho surgeries, and for the treatment of DVT and PE. However, it has several adverse reactions including peripheral edema, dizziness, headache, bruising, diarrhea, hematuria, and bleeding. Apixapan is a selective Xa inhibitor with this black box warning but is not specifically indicated for use for the prevention of strokes in patients with a-fib. Fondaparinux sodium is also a selective Xa inhibitor but has neither this black box warning nor this indication. Enoxaparin has this black box warning, but is not a selective Xa inhibitor and is not used for prevention of strokes in patients with a-fib.

Increased Anticoagulants Which of the following medications when taken with heparins, can cause an increased anticoagulant effect (bleeding risk)? Acetaminophen, oral anticoagulants, and antithrombotics Aspirin and other NSAIDs, oral anticoagulants, antiplatelets, and thrombolytics Antithrombotics, oral antibiotics, and prothrombins Aspirin and other NSAIDs, oral antibiotics, and antithrombotics

Taken with heparins, aspirin and other NSAIDs, oral anticoagulants, antiplatelets, and thrombolytics can cause an increased anticoagulant effect (bleeding risk). The other choices do not have coagulation properties that impact anticoagulants.

Warfarin Which of the following statements regarding warfarin are accurate? Select all that apply. It takes several days to reach therapeutic levels It is the most commonly prescribed parenteral anticoagulant There is a black box warning regarding bleeding risk specific to warfarin To treat warfarin toxicity, high doses of diluted vitamin K intravenously can reverse the effects within 6 hours

It takes several days for warfarin to reach therapeutic levels. It is the most commonly prescribed ORAL anticoagulant. There is a black box warning regarding bleeding risk specific to warfarin. To treat warfarin toxicity, high doses of diluted Vitamin K (phytonadione) intravenously can reverse the effects within 6 hours.

True statements:​ Unfractionated heparin is commonly known as simply "heparin"​ Heparin used therapeutically requires frequent monitoring of serum bleeding times​ ​Enoxaparin has a higher degree of bioavailability and longer elimination half-life than heparin​ ​False statements: ​ ​Low-molecular-weight heparins (LMWHs) require frequent monitoring of serum bleeding times​ Heparin when used as a DVT prophylactic and as a catheter flush require additional monitoring of serum bleeding times ​ Dalteparin is a type of unfractionated heparin ​ LMWHs do not require frequent monitoring of serum bleeding times due to its more predictable anticoagulant response. Heparin when used as a DVT prophylactic and as a catheter flush does not require additional monitoring of serum bleeding times. Dalteparin is a type of LMWH.

Abigatran - Direct thrombin inhibitor Direct thrombin inhibitors - Inhibit thrombin (clotting factor IIa) Heparin - Requires frequent monitoring of serum bleeding times (such as aPTT and INR) to determine if therapeutic level has been reached and if toxicity is present Low-molecular-weight heparins (LMWHs) - Do not require frequent monitoring of serum bleeding times due to its more predictable anticoagulant response Non-steroidal anti-inflammatory (NSAIDs) - When taken with heparins can cause an increased bleeding risk due to decreased platelet activity Cordarone - When taken with warfarin causes a 50% or higher increase in INR Rivaroxaban - The first oral Xa inhibitor to become available

Thromboembolic Event Which of the following patients is least at risk of a thromboembolic event? Someone on a direct flight from Detroit, Michigan to Sydney, Australia Someone who has been in a coma for a week following a stroke Someone who has a broken foot and is learning to walk with an orthopedic boot Someone who has a mechanical heart valve Someone recovering from a bilateral knee replacement

All of the choices are examples of patients who are most at risk of a thromboembolic event other than the patient who has a broken foot and is learning to walk with an orthopedic boot. While there may certainly a risk for this patient, this person is least at risk in comparison to the others because he/she is ambulatory rather than immobile and the injury was not serious or required a long surgery to repair it.

Indications of Use Given their general mechanism of action, anticoagulants are indicated for which of these uses? Select all that apply. Prevent myocardial infarction Prevention thrombus formation that may result from a long plane ride Promote thrombus formation on and/or around mechanical heart valves Prevention of emboli associated with ambulation following surgery Prevent stroke Dissolving thrombi that have formed Preventing thrombi formation Treatment of unstable angina Treat deep vein thrombosis Treat pulmonary embolism

Anticoagulants are used to: Prevent thrombus formation that may result from a long plane ride Treat unstable angina Treat deep vein thrombosis Prevent stroke Prevent thrombi formation Treat pulmonary embolism Prevent myocardial infarction Anticoagulants are not used to: Prevent emboli associated with ambulation following surgery Dissolve thrombi that have formed Promote thrombus formation on and/or around mechanical heart valves

Adverse Effects What are the most common adverse effects for anticoagulants in general? Select all that apply. Thrombocytosis Thrombocytopenia Abdominal cramps Necrosis of the skin and "purple toes" syndrome Bleeding Peripheral edema Hypokalemia

Bleeding, GI upset (such as nausea, vomiting and abdominal cramps), and thrombocytopenia (low platelets) are adverse effects common to all anticoagulants. Thrombocytosis is the term for a high platelet count. Hypokalemia is not common to all anticoagulants, but is a possible adverse effect of fondaparinux, a selective factor Xa inhibitor. Necrosis of the skin and "purple toes" syndrome is a possible warning sign of warfarin toxicity. Peripheral edema is a possible adverse effect of rivaroxaban

Anticoagulant Subclasses Which of these anticoagulants belongs to the subclass heparins? enoxaparin rivaroxaban warfarin clopidogrel

Enoxaparin is a type of heparin known as low-molecular-weight heparins (LMWHs) Clopidogrel is an antiplatelet drug Warfarin is an anticoagulant, but is not a heparin Rivaroxaban is a selective factor Xa inhibitor (an anticoagulant but not a heparin)

Actions of Anticoagulants Anticoagulants perform which of the following actions? Lyse pre-formed clots Breakdown fibrin Act directly on platelet aggregation Prevent thrombosis

Prevent Thrombosis Anticoagulants are also known as antithrombotic drugs because they (in general) prevent and treat thrombosis (clot formation),and prevent embolus (dislodging and mobilization of a thrombus that has formed on the wall of a blood vessel). However, anticoagulants do not directly affect/dissolve thrombi that have already formed.

Adverse Effects Which of the following are medications used for treatment of adverse effects associated with heparin? Select all that apply. protamine sulfate idarucizumab prothrombin complex concentrate (human) Direct thrombin inhibitors vitamin K

Heparin-induced thrombocytopenia is a possible adverse effect associated with heparin and is treated with direct thrombin inhibitors. Heparin toxicity is treated with the reversal drug protamine sulfate intravenously in severe cases of heparin toxicity. Prothrombin complex concentrate (human) is administered for life-threatening bleeding associated with warfarin. Idarucizumab is an antidote specific to dabigatran etexila which reverses its anticoagulant effects when the patient requires emergency surgery or has life-threatening or uncontrolled bleeding. Vitamin K is a reversal drug for warfarin and does not treat adverse effects associated with heparin.

Coumarins How do coumarins prevent thrombus formation? Inhibiting vitamin K-dependent clotting factors Breaking down the fibrin in clots Working with other drug classes to decrease the thickness of blood Directly impacting platelet aggregation

Inhibiting vitamin K-dependent Coumarins work to prevent thrombus formation within the coagulation cascade system by inhibiting vitamin K-dependent clotting factors II, VII, IX, and X by inhibiting the production of the vitamin K they need. This ultimately prevents the formation of clots (thrombi). They do not directly breakdown clots, impact platelet function, or decrease the viscosity of blood.

Categories of Heparins Which of the following are categories of heparins? Select all that apply. Direct thrombin inhibitors Low molecular-weight heparins (LMWHs) Coumarins Unfractionated heparin Selective factor Xa inhibitors

Unfractionated heparin and low-molecular-weight heparins (LMWHs) are the categories of heparins.

Heparin Toxicity Which of the following statements are correct regarding heparin toxicity? Select all that apply. Heparin toxicity may be treated intravenously with the reversal drug protamine sulfate in severe cases The toxic effects of heparin may be reversed by discontinuing heparin alone The heparin must be stopped immediately Because of heparin's long half life, the toxic effects of heparin cannot reversed by discontinuing heparin alone

With heparin toxicity, the heparin must be stopped immediately. However, because of heparin's short half life (1-2 hours), the toxic effects of heparin may be reversed by discontinuing heparin alone. Heparin toxicity may be treated intravenously with the reversal drug protamine sulfate in severe cases.