Chapter 16: Drugs Affecting the Hematologic System

Common anticoagulants

Platelet inhibitors, direct thrombin inhibitors, indirect thrombin inhibitors, & vitamin K antagonists.

Platelet inhibitors prevent

Clotting in blood vessels

Platelet inhibitors block the ability of

Platelets to stick and aggregate (group together) to form a platelet plug.

What are common platelet inhibitors?

Aspirin, clopidogrel, dipyridamole, eptifibatide, prasugrel, ticlopindine, tirofiban, & cilostazol.

Expected side effects of Platelet Inhibitors

Bleeding, easy bruising, diarrhea, nausea, dyspepsia, vomiting, flatulence, anorexia, rash, & pruritus.

Adverse effects of Platelet Inhibitors

Excessive and sudden bleeding and allergic reaction.

Platelet inhibitors taken with other drugs that alter coagulation can cause

Excessive bleeding

Platelet inhibitors variable interactions

Antacids, cimetidine, digoxin, & theophylline.

Decreases effectiveness of anticoagulants

Green, leafy veggies containing vitamin K

When taking platelet inhibitors, alcohol can

Increase bleeding risk.

When assessing an individual who is using platelet inhibitors, obtain their

Drug history, bleeding/bruising, & any signs of internal bleeding

Heparin sodium increases the action of

Antithrombin III (heparin cofactor) on several other coagulation factors to slow new clot development.

5 categories of Direct thrombin inhibitors

Heparin sodium, coumarin, platelet aggregation inhibitors, direct thrombin inhibitors, & protease-activated receptor-1 antagonist.

Coumarin limits the formation of

Blood coagulation factors II, VII, IX, and X in the liver by interfering with vitamin K.

Direct thrombin inhibitors act much like

Warfarin but act to stop coagulation process.

Protease-activated receptor-1 antagonists are used specifically in individuals who have

Had myocardial infarction or peripheral arterial disease already and should lower the risk of another heart attack, stroke, or death of cardiovascular causes.

Direct thrombin inhibitors prevent

New thrombus formation

Direct thrombin inhibitors do not

Dissolve clots that have already occured.

Prophylactic

After surgery involving heart or circulatory system.

Direct thrombin inhibitors are commonly used in patients at risk for

Systemic embolism and stroke, especially those with a-fib that is not caused by a heart valve problem.

Expected side effects of direct thrombin inhibitors

Bleeding & easy bruising

Adverse reactions to direct thrombin inhibitors

Excessive bleeding & thrombocytopenia

Early signs of overdose/internal bleeding from direct thrombin inhibitors include

Bleeding from gums while brushing teeth, excessive bleeding/oozing from cuts, unexplained nose bleeds, & unusually heavy/unexpected periods in women.

What do indirect thrombin inhibitors do

Clot formation by increasing the amount and action of protein antithrombin III; prevents new clot formation, or stops existing clots from growing in size.

Expected side effects of indirect thrombin inhibitors

Easy bleeding/bruising, pain, redness, warmth, irritation, & skin changes at injection site.

Adverse reactions of indirect thrombin inhibitors

Hemorrhage, thrombocytopenia, shortness of breath, wheezing, chills, fever, alopecia, & hypersensitivity reaction.

Serious reactions from Indirect thrombin inhibitors

Heparin-induced thrombocytopenia and heparin-induced thrombocytopenia and thrombosis.

Drug interactions with indirect thrombin inhibitors

Aspirin, NSAIDs, glucocorticoids, & other anticoagulants.

Use indirect thrombin inhibitors cautiously in patients with

Liver/kidney disease, hypertension, during a women's period, after delivery, & patients with indwelling catheters.

Indirect thrombin inhibitors route

Intravenous injection, intravenous infusion, or subcutaneous injection.

Indirect thrombin inhibitors are never given

Intramuscular Route

When preparing indirect thrombin inhibitors, NEVER

Shake bottle

Indirect thrombin inhibitors can not be

Piggybacked with other drugs or mixed with other drugs in a syringe.

Vitamin K antagonists inhibit the

Enzyme needed for final activation of vitamin K

Vitamin K antagonists prevent

Blood clots and emboli

Expected side effects of vitamin K antagonists

Bleeding and easy bruising.

Adverse reactions of Vitamin K antagonists

Excessive bleeding, frank blood/dark, tarry stools; coffee- colored vomit with a high dosage.

Fibrinolytic Drugs convert

Plasminogen to enzyme plasmin

Fibrinolytic drugs break down

Fibrin clots, fibrinogen, & other plasma proteins.

Primary uses of Fibrinolytic drugs

Acute myocardia infarctions, acute pulmonary emboli, acute ischemic stroke, & acute arterial occlusion.

Expected side effects when using Fibrinolytic drugs

Bleeding

Adverse reactions of fibrinolytic drugs

Severe bleeding, shortness of breath, wheezing, chest tightness, facial swelling, rash, or hives.

Fibrinolytic drugs result in an increased

Stroke risk

Giving fibrinolytic drugs with other anticoagulants may

Increase potential for bleeding.

Fibrinolytic drugs are given in

Life-threatening situations of stroke or myocardial infarction.

Erythropoiesis-stimuating agents reduces the need for

Transfusions and reduces complications of transfusions (fluid overload)

Expected side effects of Erythropoeisis-stimulating agents

Pain at injection site, generalized body aches/pain, rash, redness, or warmth to injection site.

Adverse reactions of erythropoesis stimulating agents

Hypertension, blood clots, stroke, heart attack, & severe allergic reaction.

When a patient is taking erythropoeisis-stimulating agents, monitor for

Allergic reaction (rash, wheezing, facial swelling, difficulty breathing, & hypotension), signs of stroke, chest pain, shortness of air, & increases in BP

Ferrous sulfate is a common treatment of

Iron deficiency anemia

Expected side effects of ferrous sulfate

Constipation, dark colored stool, GI irritation, & nausea.

Adverse reactions to ferrous sulfate

Hypersensitivity reaction & iron overdose.

When giving a patient ferrous sulfate, monitor for

Signs of anemia (tachycardia, chest pain, SOA)

Iron dextran is commonly used for

Treatment of iron deficiency anemia in patients for whom oral iron is not effective/feasible.

Expected side effects when giving iron dextran

Pain & brown-colored pigmentation at injection site along with constipation.

Adverse reactions for iron dextran

Black box warning for allergic reaction, severe low BP, diarrhea/vomiting, sterile abscess at injection site.

Clot

Semisolid amount of coagulated (thickened) blood that blocks blood flow in a blood vessel (AKA thrombus)

Deep Vein Thrombosis (DVT)

A clot lying in a deep vein, usually in the leg.

Direct thrombin inhibitors (DTIs)

Anticoagulants that delay blood clotting by directly inhibiting the enzyme thrombin

Embolism

Blockage in an artery caused by a blood clot/air bubble

Erythropoiesis-stimulating agent (ESA)

Synthetic form of the hormone erythropoietin.

Erythropoietin stimulates the

Bone marrow to make more red blood cells at a faster rate.

Fibrin

Protein formed from fibrinogen during clotting process

Fibrins netlike structure traps

Blood cells & platelets, building up a spongy mass that gradually hardens and contracts to form a blood clot.

Fibrinogen

Protein found in the blood plasma that is converted to fibrin to help form a blood clot.

Fibrinolytic drug

Drug that uses enzymes to dissolve fibrin in a clot; AKA thrombolytic drug/clot buster.

Indirect thrombin inhibitors (ITIs)

Anticoagulant drugs that reduce clot formation by increasing the amount and action of the protein antithrombin III.

Platelet inhibitors

Drugs that interfere with blood clotting in the arteries by preventing platelets from sticking and clumping together.

Thrombin

Enzyme that acts on fibrinogen (protein found in blood plasma) to convert it to fibrin to help clots form.

Vitamin K antagonist

Anticoagulant drug that interferes with blood clotting by reducing the amount of vitamin K available to help the liver form clotting factors.

Fibrinolytic drugs dissolve

Existing clots

Fibrinolytic drugs reduce the

Formation of new clots

All anticoagulants and fibrinolytic drugs greatly increase the risk of

Excessive bleeding.

Before starting anticoagulation therapy, ask the patient

Of any other drugs (OTC & prescribed), vitamins, and supplements they take; check with pharmacist to determine whether any of them affect blood clotting.

When injecting subcutaneous heparin, do NOT

Pull back on syringe to aspirate blood/move the needle in the tissue during injection.

Antidote for heparin overdose

Protamine sulfate

Risk of allergic reactions is higher with heparin than other anticoagulants because

Heparin is made from animal products.

Teratogenic means

Causes birth defects

Warfarin is teratogenic and should never

Be used during pregnancy

Antidote for warfarin overdose

Vitamin K injection (aquamephyton)

A patient may receive warfarin at the same time as

Heparin is received

All fibrinolytic drugs are given

Intravenously

All fibrinolytic drugs are

High-alert drugs

Severe, fatal allergic reactions can occur with

Iron preparations, especially when given IV.

Iron dextran is a

High-alert drug with a black box warning.