Hematologic Pharmacology Jennifer Kean MSN RN CCRN Parenteral

Hematologic Pharmacology Jennifer Kean MSN, RN, CCRN

Parenteral anticoagulants o Heparin o Low molecular weight heparins o o Enoxaparin (Lovenox) o Dalteparin Activated factor Xa inhibitor o Fondaparinux

Purpose o Expected pharmacological action: o Heparin prevents clotting by activating antithrombin, thereby indirectly inactivating both thrombin and factor Xa o This inhibits fibrin formation o Enoxaparin primarily inactivates factor Xa and is much less able to inactivate thrombin o Fondaparinux inactivates factor Xa, thus decreasing thrombin production

Therapeutic uses o o Heparin o Treats disorders needing prompt anticoagulation (evolving stroke, pulmonary embolism, massive DVT) o As an adjunct for patients having open heart surgery or hemodialysis, or as adjunct therapy for myocardial infarction o Low dose for prophylaxis against post-op DVT Low-molecular weight heparins o Prevent DVT in post-op patients o Treat acute DVT or PE along with warfarin

Complications o o Hemorrhage due to overdose: nursing actions o Monitor vital signs o Withhold heparin and administer protamine sulfate o Monitor PTT every 4 -6 hours o Observe for bleeding, tarry stools, bruising, petechiae, tachycardia Low platelet count (heparin-induced thrombocytopenia) o Monitor platelet count periodically o Toxicity/overdose: give protamine sulfate (the antidote) o Neurologic damage due too hematoma formation from spinal or epidural anesthesia

Contraindications/precautions o Thrombocytopenia and unexplained bleeding o Surgery of the eye, brain and spinal cord o Lumbar puncture o Patients who have hemophilia, increased capillary permeability (CHF), dissecting aneurysm, hepatic or kidney disease o Interactions: o Aspirin, NSAIDs, can increase risk for bleeding o Avoid concurrent use whenever possible o Take precautionary measures to avoid injury

Nursing administration o Document baseline vital signs, CBC, platelet count, H&H o Read the label carefully- heparin comes n different concentrations o Monitor a. PTT o Administer sub-q injections in the abdomen, deep into the tissue, at a 90 -degree angle and at least 2 inches away from the umbilicus o Do not aspirate and rotate injection sites o Instruct client to report unusual bleeding: gums, tarry stools, bruising, etc. and to use an electric razor o Instruct client to avoid use of OTC NSAIDs (ibuprofen and naproxen; acetaminophen is ok)

Nursing evaluation o Indications of effectiveness include the following: o Heparin: a. PTT of 60 -80 seconds (2 -3 x the baseline) o Heparin, enoxaparin, and fondaparinux: no development or no further development of venous thrombi or emboli

Oral anticoagulants: warfarin (Coumadin) o Expected action: oral anticoagulants antagonize vitamin K, thereby preventing the synthesis of 4 coagulation factors(VII, IX, X, prothrombin) o Therapeutic uses: o o Prevent DVT and PE o Prevent thrombus formation in patients with afib or prosthetic heart valves o Prevent recurrent MI, TIA, PE, and DVT Complications: o Hemorrhage: monitor vital signs, PT/INR; for overdose, administer vitamin K o REMEMBER: for heparin, monitor PTT and for warfarin, monitor PT/INR

Contraindications/precautions o Pregnancy: warfarin is pregnancy risk category X due to high risk of fetal hemorrhage o Breastfeeding, thrombocytopenia, and unusual bleeding o Surgery of the eye, brain, spinal cord or lumbar puncture o Vitamin K deficiencies, liver disorders, and alcoholism o Hemophilia, dissecting aneurysm, peptic ulcer disease, severe hypotension

Interactions o Concurrent use of: aspirin, clopidogrel, dipyridamole, ticlopidine, abciximab, glucocorticoids, sulfonamides, acetaminophen, cimetidine, and parenteral cephalosporins- all increase risk of bleeding o Discourage concurrent use if possible o Monitor PT/INR o Check OTC med use o Concurrent use of: phenobarbital, carbamezipine, rifampin, phenytoin, oral contraceptives, and vitamin K- decrease effectiveness of warfarin o Excessive intake of foods high in vitamin K (dark green leafy vegetables)decrease effectiveness of warfarin

Nursing administration o Give orally at the same time each day o Document baseline vital signs, PT/INR, CBC, platelets, and H&H o It can take 1 week or more to reach therapeutic levels; the patient may still have to take heparin with warfarin until the PT/INR reaches 2 -3 x the baseline o Instruct client to avoid alcohol and OTC meds o If client needs surgery, warfarin must be discontinued several days prior to

Direct thrombin inhibitors: dabigatran, argatroban o These meds work by inhibiting thrombin, thus preventing a thrombus from forming o Therapeutic uses: o Dabigatran prevents stroke or embolism in patients with afib o Argatroban prevents or treats thrombosis in patients who cannot take heparin due to allergy or heparin-induced thrombocytopenia (HIT)

Complications and Contraindications o Unusual or unexplained bleeding: GI, GU, intracranial o GI discomfort, nausea, vomiting, ulcer formation: take with food o Back pain, nausea, hypotension and headache o CONTRAINDICATIONS: o Pregnancy or breastfeeding o Active bleeding or allergy o Liver or kidney impairment

Interactions o Rifampin decreases levels of drug in body o Other thrombolytics and anticoagulants can increase the risk for bleeding o Nursing administration: o Swallow capsule whole, do not crush (dabigatran) o Argatroban is given IV via continuous infusion o Periodically check PTT and PT/INR

Direct inhibitors of factor Xa: rivaroxaban and apixaban o Provide anticoagulation by directly inhibiting factor Xa o Treats afib and prevents DVT? PE in patients having joint replacement surgery; also prevents stroke and embolism in patients with nonvalvular afib o No antidote is available for severe bleeding o Monitor Hgb and Hct, report unusual bruising or bleeding o Document baseline LFTs o Contraindications/precautions: pregnancy, allergy, other anticoagulants, liver or kidney impairment o Interactions: erythromycin, diltiazem, verapamil, amiodarone: increase riak for bleeding; rifampin, carbamezapine, phenytoin: decrease therapeutic levels

Antiplatelets o Aspirin, abciximab, clopidogrel, ticlodopine, prasugrel, ticagrelor o Purpose: prevent platelets from clumping together by inhibiting enzymes and factors that usually lead to arterial clotting and inhibit platelet aggregation; these meds alter bleeding time o Therapeutic uses: prevention of acute MI and also reinfarction, prevent ischemic strokes and TIAs, acute coronary syndrome, intermittent claudication and thromboembolism following surgery o Administration: oral and IV

Complications o GI effects: nausea, vomiting, dyspepsia- take with food o Hemorrhagic stroke o Gastric bleeding, thrombocytopenia o Tinnitus, hearing loss o Hypotension and bradycardia o Diarrhea o Headache, dizziness

Contraindications/precautions/interactions o Pregnancy/breastfeeding o Bleeding disorders and thrombocytopenia o Peptic ulcer disease, liver or kidney disease o Concurrent use of other antiplatelets or anticoagulants o Corticosteroids can decrease the effects of aspirin o Caffeine can increase aspirin absorption o Proton pump inhibitors decrease effectiveness

Thrombolytic medications: alteplase (TPA), reteplase o Expected action: these meds dissolve clots that have already formed o Used to treat acute MI, massive PE, ischemic stroke; given IV only o Complications: serious risk of bleeding-internal and superficial o o Limit venipuncture and injections o Apply pressure dressings to recent wounds o Monitor for changes in vital signs and LOC o Monitor PTT, PT/INR, H&H Contraindications: pregnancy, prior intractranial hemorrhage, active internal bleeding, surgery within 2 months, pericarditis or endocarditis, brain tumors, liver or kidney disorders

Interactions and nursing administration o Concurrent use of other meds that cause bleeding o Outcomes are much better if these meds are administered within 2 -4 hours of onset of symptoms o Should only be given where the patient can be closely monitored (ICU) o Document baseline labs o Limit injections and venipunctures o Administer proton pump inhibitors to prevent/reduce GI bleeding

Growth factors o Therapeutic uses: o Replacement of neutrophils and platelets after chemotherapy o Hastening of bone marrow function after bone marrow transplant o Increase red blood cell production in patients with chronic kidney disease o Erythropoetin (Epogen): increases RBC production o Filgastrim (Neupogen): increases WBC production o Interleukin-11: increases platelet production

Erythropoetin o Used for anemia due to chronic kidney disease or chemotherapy o Complications: cardiac events from increased RBCs o Monitor H&H levels and blood pressure o Seizures from a too-rapid rise in blood cell counts o DVT o Headache, body aches o Contraindications: uncontrolled hypertension, pregnancy, some cancers o Nursing administration: check BP often, do not mix with other meds in the syringe (always given IV), give three times per week, monitor H&H and labs

Filgastrim o Therapeutic uses: increase neutrophil count after chemotherapy, decrease risk of infection, build up stem cells before transplant o Complications: bone pain- give acetaminophen, leukocytosis-monitor CBC 3 x/week, splenomegaly and risk of splenic rupture o Contraindications: pregnancy/breastfeeding, weight < 45 kg (99 lbs), cancer of the bone marrow, sickle cell anemia, respiratory disease o Nursing administration: do not agitate the vial of medication, monitor CBC, teach pt. sub-q administration for home care

Interleukin-11 o Uses: to increase the production of platelets, decrease thrombocytopenia and the need for platelet transfusions o Complications: peripheral edema, dyspnea on exertion- monitor I&O, , tachycardia, afib- monitor HR and EKG, transient blurring of vision- withhold med and notify provider, allergic rxn and anaphylaxis o Contraindications: cancer of the bone marrow, heart failure of pleural effusion, cardiac dysrhythmias o Nursing administration: document baseline CBC and platelet count, administer once daily sub-q