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Hematologic Drugs
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
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)
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.
Heparin
The mechanism of action of HeparinHeparin (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.
Heparins
Clinical Indications of Heparins• deep vein thrombosis • pulmonary embolism• coronary thrombosis, • patients with artificial heart valves and stroke patients
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.
HeparinsPharmacokinetics: 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
Heparins
The Nursing process and HeparinAssessment• 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.
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
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.
Heparins
Evaluation• Monitor the effectiveness of the medication:
– Decreased formation of clot– PTT is 2x the normal
The Oral Anticoagulants
There are three commonly used oral anticoagulant agents in the hospital
• Warfarin- most commonly used, synthesized from dicumarol
• Dicumarol• Anisindone
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.
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.
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
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.
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
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.
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.
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
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
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
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.
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.
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
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
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
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
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.
The Thrombolytics
Clinical indications of thrombolytics• Myocardial infarction• Pulmonary embolism• Thromboemboilic stroke• Peripheral arterial thrombosis and • to open clotted IV catheters.
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.
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.
The Thrombolytics
Evaluation• Monitor the effectiveness of the medication
– Clot lysis
The Agents to treat bleeding
• Aminocaproic acid and tranexamic acid– These are fibrin stabilizers that maintain or
stabilize the clot in the bleeding vessels
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.
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.
AntihyperlipidemicsThese 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
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.
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.
The antianemics: Iron preparations and Epoetin
Iron preparations• Iron is important for hemoglobin formation.
The iron preparations are:• Ferrous sulfate• Ferrous fumarate• Ferrous gluconate
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
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.
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.
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.
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.
ErythropoietinThe 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.
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.
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
ErythropoietinImplementation• 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
Erythropoietin
Evaluation
• Monitor patient response to the drug= increased hemoglobin