Pharmacology Hematologic Drugs
- 2. Hematologic drugs There are numerous agents utilized to maintain, preserve and restore circulation. The three important dysfunction of blood are thrombosis, bleeding and anemia are commonly treated with various agents. The common ones that nurses must REVIEW are the: Anticoagulants Antilipemics Antiplatelets (antithombotics) Thrombolytics Anti-anemics or Hematinics Drugs to treat bleeding
- 3. The Anti-Coagulants The anticoagulants interfere with the coagulation process by interfering with the clotting cascade and thrombin formation. These agents are used to inhibit clot formation, but they do NOT dissolve existing clots. The Anticoagulants commonly used are: Heparin Warfarin (Coumadin) Dicumarol Anisindione (Miradon)
- 4. Heparins These are anticoagulants given orally or parenterally- SQ and IV. Heparin is naturally found in the human liver that normally prevents clot formation. Heparin is strongly acidic because of the presence of sulfate and carboxylic acid groups in the heparin chain.
- 5. Heparin The mechanism of action of Heparin Heparin (Liquamen Sodium) acts prophylactically to prevent the formation of blood clots in the vasculature. It combines with ANTITHROMBIN III, a substance in our blood sometimes called heparin factor that inactivates THROMBIN. By inhibiting the action of thrombin, conversion of fibrinogen to fibrin does not occur and the formation of a fibrin clot is prevented.
- 6. Heparins Clinical Indications of Heparins deep vein thrombosis pulmonary embolism coronary thrombosis, patients with artificial heart valves and stroke patients
- 7. Heparins Contraindications of heparin Anticoagulants are not given to patients with bleeding disorders, peptic ulcers and patients who underwent recent eye/brain/spinal surgery. It is NOT given to patients with severe liver and renal disease, hemophilia, and CVA. Heparin is a large protein molecule that cannot pass through the placenta easily and can be given to pregnant women.
- 8. Heparins Pharmacokinetics: the Adverse Effects of Heparin INCREASES the clotting time and also DECREASES the platelet count. In this regard, monitoring of the aPTT/PTT (N= 20-30 seconds) and platelet count is required. Hematologic effects: increased bleeding, thrombocytopenia Skin-itching and burning Hypersensitivity reactions like chills, fever, urticaria or anaphylaxis can occur since heparin is obtained from animal sources. Life threatening adverse effect is Hemorrhage
- 9. Heparins The Nursing process and Heparin Assessment Patient history Physical examination- the nurse obtains baseline vital signs and physical assessment. She must obtain laboratory results of the complete blood count, platelet count and activated partial thromboplastin time (aPTT), and clotting time.
- 10. Heparins IMPLEMENTATION: Monitor the aPTT closely (it should be 1.5-2.5 times normal value ) Monitor vital signs and hematological status regularly. Monitor signs of bleeding- hematuria, epistaxis, ecchymoses, Hypotension and occult blood in stool Have available ANTIDOTE for heparin- PROTAMIME SULFATE
- 11. Heparins IMPLEMENTATION: Instruct the client not to use any over the counter drug without notifying the physician Administer heparin subcutaneously in the abdominal region, using a 25-28-gauge needle at a 90-degree angle. DO NOT MASSAGE OR RUB THE AREA as this may cause bruising. Advise patient not to smoke, use electric razors to shave, use soft toothbrush and control sudden hemorrhage by direct pressure for 5-10 minutes. Provide gently skin and oral care.
- 12. Heparins Evaluation Monitor the effectiveness of the medication: Decreased formation of clot PTT is 2x the normal
- 13. The Oral Anticoagulants There are three commonly used oral anticoagulant agents in the hospital Warfarin- most commonly used, synthesized from dicumarol Dicumarol Anisindone
- 14. The Oral Anticoagulants Pharmacodynamics: the mechanism of Action of the Oral agents These agents INHIBIT the liver synthesis of the Vitamin K clotting factors – factors II, VII, IX, and X.
- 15. The Oral Anticoagulants Clinical indications of oral anticoagulants These drugs are used to prevent blood clotting in patients with thrombophlebitis pulmonary embolism and embolism from atrial fibrillation. Because Warfarin crosses the placental barrier, it is NOT given to pregnant mothers.
- 16. The Oral Anticoagulants Contraindications and precautions Oral anti-coagulants are NOT given to patients with bleeding disorders, peptic ulcers, severe renal/liver diseases, hemophilia, CVA blood dyscrasias and eclampsia. It is NOT given to pregnant mothers because it is teratogenic and can cause abortion
- 17. The Oral Anticoagulants Pharmacokinetics: Oral anticoagulants prolong the clotting time and are monitored by the Prothrombine Time ( PT- average of 9-12 seconds ). This is usually performed before administering the next dose. The PT level should be 1.5-2 times the reference value to be therapeutic . The normal INR is 1-2. If the patient is on oral anticoagulant therapy, the INR is maintained at an INR of 2.0-3.0. If the INR is below the recommended range, warfarin is increased. If it is above the recommended range, warfarin should be reduced.
- 18. The Oral Anticoagulants Pharmacokinetics: the Adverse Effects of Warfarin Hematologic effects: increased bleeding , thrombocytopenia Anorexia, nausea, vomiting, diarrhea, abdominal cramps, rash and fever. Alopecia, bone marrow depression, and dermatitis. Life threatening adverse effect is Hemorrhage
- 19. The Oral Anticoagulants The Nursing process and Warfarin Assessment Patient history-. The nurse determines the current medications taken, PREGNANCY, and history of recent surgery. Physical examination- the nurse obtains baseline vital signs and physical assessment. laboratory results of the complete blood count, platelet count and Prothrombin time , INR and clotting time.
- 20. The Oral Anticoagulants Implementation Monitor vital signs and hematological status Monitor signs of bleeding- hematuria, epistaxis, black tarry stools, echymoses, Hypotension and occult blood in stool Have available ANTIDOTE for warfarin- VITAMIN K or phytonadione .
- 21. The Oral Anticoagulants Implementation Advise patient not to smoke, use electric razors to shave, use soft toothbrush and control sudden hemorrhage by direct pressure for 5-10 minutes. Provide gently skin and oral care. Instruct the patient to avoid foods high in vitamin K like spinach, nuts
- 22. The Oral Anticoagulants Evaluation Monitor the effectiveness of the medication Decreased formation of blood clots Check the PT and INR Should be 2x the normal
- 23. Anti-platelets These are agents decrease the formation of the platelet plug by decreasing the responsiveness of the platelets to various stimuli that would cause them to stick and combine together on a vessel wall Aspirin Dipyridamole Sulfinpyrazone Ticlopidine Clopidogrel Glycoprotein receptor antagonists Abciximab Eptifibatide Tirofiban
- 24. Anti-platelets The mechanism of action of platelet inhibitors These agents INHIBIT the aggregation of platelets in the clotting process by blocking receptor sites on the platelet membrane, preventing platelet-to-platelet interaction, thereby prolonging the bleeding time.
- 25. Anti-platelets Clinical indications Prevention of myocardial infarction and stroke Prevention of a repeat myocardial infarction Prevention of stroke for those with transient ischemic attack In patients with graft to maintain its patency.
- 26. Anti-platelets Pharmacodynamics: the adverse effects of Antiplatelets Bleeding is the most common side effect GIT- gum bleeding, gastric bleeding , tarry stools CNS- headache, dizziness and weakness Skin- petechiae, bruising, allergy ASPIRIN toxicity: tinnitus
- 27. Anti-platelets Nursing considerations Determine if the patient is allergic or sensitive to the medications Monitor closely the vital signs and bleeding areas Instruct the patient to take drug with food Monitor the bleeding time, clotting time and platelet count
- 28. Anti-platelets Nursing considerations Suggest safety measures including the use of an electric razor and avoidance of contact sports. Provide increased precautions against bleeding during invasive procedures. Use pressure dressings and ice to decrease excessive blood loss. Monitor for tinnitus
- 29. The Thrombolytics These thrombolytic agents are used to activate the natural anticlotting fibrinolytic mechanism to convert plasminogen to plasmin, which destroys and breaks down the fibrin threads in the blood clot (FIBRINOLYSIS). The result is clot disintegration. The commonly used thrombolytics “---ase” Streptokinase Urokinase Tissue plasminogen activator (t-PA) or alteplase Anistreplase Reteplase
- 30. The Thrombolytics The mechanisms of actions of each agent Streptokinase and urokinase are ENZYMES that act SYSTEMICALLY to dissolve the blood clots by activating plasminogen to plasmin.
- 31. The Thrombolytics Clinical indications of thrombolytics Myocardial infarction Pulmonary embolism Thromboemboilic stroke Peripheral arterial thrombosis and to open clotted IV catheters.
- 32. The Thrombolytics Pharmacokinetics: The adverse effects of Streptokinase CVS- Hypotension and dysrhythmias (usually upon reperfusion of the heart) Hematological: increased bleeding- the most common effect. Headache, nausea, flush, rash and fever Allergic reaction- especially steptokinase and urokinase Major adverse effect- hemorrhage.
- 33. The Thrombolytics Implementation. Monitor signs of active bleeding from mouth and rectum bleeding- hematuria, epistaxis, echymoses Have available ANTIDOTE for thrombolytics: AMINOCAPROIC ACID! Have available blood for emergency use. Advise patient not to smoke, use electric razors to shave, use soft toothbrush and control sudden hemorrhage by direct pressure for 5-10 minutes. Provide gently skin and oral care. As much as possible, avoid frequent venipuncture.
- 34. The Thrombolytics Evaluation Monitor the effectiveness of the medication Clot lysis
- 35. The Agents to treat bleeding Aminocaproic acid and tranexamic acid These are fibrin stabilizers that maintain or stabilize the clot in the bleeding vessels
- 36. The Agents to treat bleeding Protamine sulfate This agent antagonizes the anticoagulant effects of heparin. It is derived from fish testis and is high in arginine content. The positive charge interacts with the negative charge of heparin to forma stable inactive complex.
- 37. The Agents to treat bleeding Vitamin K Vitamin K is given to antagonize the effects of the oral anticoagulants. The response to Vitamin K is slow, requiring about 24 hours thus, if immediate hemostasis or bleeding control is required, fresh frozen plasma should be ordered by the physician.
- 38. Antihyperlipidemics These drugs target the problem of elevated serum lipids Resins and bile acid sequestrants Cholestyramine Colestipol Fibric Acid Derivatives Clofibrate Gemfibrozil Fenofibrate HMG CoA reductase inhibitors= “statins” Atorvastatin Cerivastatin Fluvastatin Lovastatin Pravastatin Simvastatin Nicotinic acid Probucol
- 39. statins Pharmacodynamics: The mechanism of action of the Statins These agents INHIBIT the enzyme HMG CoA reductase in the synthesis of cholesterol. By inhibiting the important enzyme in cholesterol production in the liver, the statins decrease the plasma concentration of cholesterol and lower the LDL level with slight increase in the HDL level.
- 40. statins Therapeutic indications These agents are given to patients with CORONAY ARTERY DISEASE and hyperlipidemia, hypercholesterolemia These statins are very effective in all types of hyperlipidemias.
- 41. The antianemics: Iron preparations and Epoetin Iron preparations Iron is important for hemoglobin formation. The iron preparations are: Ferrous sulfate Ferrous fumarate Ferrous gluconate
- 42. The antianemics: Iron preparations and Epoetin Side-effects: GIT- constipation (usually), diarrhea, vomiting, epigastric pain, gastric ulceration and darkening of stools. Liquid preparation can stain the teeth, and injectable iron can cause tissue discoloration Other- dizziness
- 43. The antianemics: Iron preparations and Epoetin Drug-Drug interaction Tetracyclines and penicillamine- combine with iron preparations and render the iron unabsorbable. Antacids and cimetidine- decrease iron absorption and effects Foods can impair iron absorption but they should be taken with iron to reduce GI discomfort. Milk containing foods, coffee, tea and eggs are NOT given with iron because they delay iron absorption.
- 44. The antianemics: Iron preparations and Epoetin Implementation Encourage the patient to eat iron-rich foods like liver, lean meat, egg yolk, dried beans, green leafy vegetables. Administer iron preparations orally with foods to decrease GI discomfort. If increased absorption is necessary, administer IN BETWEEN meals with full glass of water or juice. It is best to offer citrus juices because the vitamin C content can increase iron absorption. Instruct the patient to swallow the whole tablet and remain upright for 30 minutes to prevent esophageal corrosion from reflux. DO NOT administer iron together with or within 1 hour of ingesting tetracyclines, antacids, milk and milk-containing products. Advise clients to increase fluid intake and consume fiber rich foods if constipation becomes a problem.
- 45. The antianemics: Iron preparations and Epoetin Implementation Warn the patient of possible iron poisoning if tablets are left within child’s reach. Emphasize that the therapeutic effect of iron therapy may not be apparent until several weeks. If injecting a parenteral iron preparation, inject DEEP IM utilizing the Z-track method to avoid leakage into the subcutaneous tissues and skin . Offer straw if giving liquid iron preparation to avoid staining the teeth. To prevent undue alarm, instruct the patient that the stools may turn black or dark green. This is a harmless occurrence.
- 46. The antianemics: Iron preparations and Epoetin Evaluation The nurse evaluates the effectiveness of the drug therapy by determining that the client is not fatigued, with absence of pallor, and with hemoglobin results within desired range .
- 47. Erythropoietin The mechanism of action of epoetin alfa (Epogen) This drug acts like the natural glycoprotein erythropoietin to stimulate the production of RBC in the bone marrow.
- 48. Erythropoietin Clinical indications It is given SUBCUTANEOUSLY or INTRAVENOUSLY for the treatment of anemia associated with renal failure or for patients on dialysis . It is also used in patients for blood transfusion to decrease the need for blood in surgical patients.
- 49. Erythropoietin Pharmacodynamics: the adverse effects of epoetin alfa CNS- headache, fatigue, asthenia, dizziness and seizures- these are due to the cellular response to the glycoprotein. GIT- nausea, vomiting and diarrhea CVS- hypertension, edema and chest pain due to increase RBC number
- 50. Erythropoietin Implementation Administer the drug SC or IV usually 3 times per week. Monitor the IV access line if given IV. Do not mix with other solutions Determine periodically the level of hematocrit and iron stores during therapy. If patient does not respond to the drug, reevaluate the cause of anemia. Maintain seizure precaution on stand by as seizure can occur. Provide comfort measures like small frequent feedings and pain medications for headache. Provide thorough health teaching: need for lifetime injection
- 51. Erythropoietin Evaluation Monitor patient response to the drug= increased hemoglobin