Blood Forming Agents, Anticoagulants, Antilipemic Flashcards
Hematopoiesis
The formation of new blood cells - RBC (Erythrocytes)
- Manufactured in bone marrow
- Immature RBCs are reticulocytes
- Lifespan is 120 days
- More than 1⁄3 of a RBC is made of hemoglobin
- WBC (Leukocytes)
- Platelets (Thrombocytes)
hemolytic anemias
Excessive destruction of RBCs
hemolytic anemias
Intrinsic RBC abnormalities:
- Sickle cell anemia
- Hereditary spherocytosis
- G6PD Deficiency
hemolytic anemias
Extrinsic mechanisms
- Drug-induced anti-RBC antibodies
- Septic shock
- Mechanical forces (certain medical devices)
Erythropoiesis-Stimulating Agents
epoetin alfa (Eprex)
epoetin alfa (Eprex)
○ Biosynthetic form of the natural hormone erythropoietin
○ Used for treatment of anemia associated with end-stage renal disease,
chemotherapy-induced anemia, and anemia associated with zidovudine therapy
(antiretroviral medication)
○ Medication is ineffective without adequate body iron stores and bone marrow function**
○ Most patients need to also receive an oral iron preparation
○ It is usually delivered 3x a week as a subcutaneous injection
epoetin alfa (Eprex) Contraindications:
○ Hemoglobin levels that are above 100mmol/L for cancer pts and 130mmol/L for pts with kidney disease
○ Drug allergy
○ Uncontrolled hypertension
○ Head and neck cancers
○ Risk of thrombosis
epoetin alfa (Eprex) Adverse effects
○ Hypertension
○ Fever
○ Headache ○ Pruritus ○ Rash
○ Nausea
○ Vomtiing
○ Injection site reaction
Iron
- It is an essential mineral in the body
- Oxygen carrier in hemoglobin and myoglobin
- Stored in the liver, spleen, and bone marrow
- Deficiency results in anemia
Dietary sources of Iron
- meats, certain vegetables and grains
- Dietary iron must be converted by gastric juices before it can be absorbed
Foods that enhance iron absorption:
- Orange juice
- Fish
- Ascorbic acid
Foods that impair iron absorption:
- Eggs*
- Corn
- Beans*
- Cereal containing phytates
Supplemental Iron
It is a Schedule II !!!
Oral iron preparations are available as ferrous salts:
- ferrous fumarate
- ferrous sulphate
- ferrous gluconate
Parenteral:
- iron dextran
- iron sucrose
- ferric gluconate
- ferumoxytol
Indications of supplemental Iron
- Prevention and treatment of iron deficiency syndromes
- Administration of iron alleviates the symptoms of iron deficiency anemia, but the
underlying cause of the anemia should be corrected*
Adverse Effects of supplemental Iron
It is a Schedule II
- Most common cause of pediatric poisoning deaths
- Nausea
- Vomiting
- Diarrhea
- Constipation
- Stomach cramps
- Pain
- TARRY STOOLS (dark green stools)
- Injectable forms cause pain upon injection
- Liquid oral temporarily discolors teeth
Iron Toxicity
Symptomatic and supportive measures:
- Suction and maintenance of the airway; correction of acidosis; control of shock and dehydration with IV fluids or blood, oxygen, and vasopressors
- Pts with severe iron intoxication, such as coma, shock, or seizures, chelation therapy with deferoxamine mesylate is intiated
Parenteral Iron
● iron dextran (Dexiron, Infufer)
○ May cause anaphylactic reactions, including major orthostatis hypotension and fatal anaphylaxis
○ A test dose of 25mg of iron dextran is administered before injection of the full dose, and then the remainder of dose is given after 1 hour
○ Not used often, replaced by newer products ferric fluconate and iron sucrose**
Parenteral Iron
● ferric gluconate (Ferrlecit)
○ Indicated for repletion of total body iron content in pts with iron deficiency anemia who are undergoing hemodialysis
** Risk for anaphylaxis is less than with iron dextran, test dose is not required
○ Doses higher than 125mg are associated with increased adverse events, including abdominal pain, dyspnea, cramps, and itching
Folic Acid
- Water-soluble, B-complex vitamin (B9)
- Essential for erythropoiesis
- Primary use is for deficiency as well as during pregnancy to prevent brain and spinal cord
defects - Malabsorption syndromes are the most common causes of deficiency
- It should not be used until actual cause of anemia is determined
- It may mask symptoms of pernicious anemia, which requires other treatment, not folic
acid* - Untreated pernicious anemia progresses to neurological damage
Cyanocobalamin- Vitamin B12
- Used to treat pernicious anemia and other megaloblastic anemias (large, abnormal, immature RBCs)
- Administered orally or parentally
- Usually administered by deep IM to treat pernicious anemia
Anemia
Nursing Process- Assessment
- Ferrous salts are contraindicated for pts with ulcerative colitis, peptic ulcer disease, liver disease, and other gastrointestinal disorders
- Iron dextran is contraindicated in all anemias except for iron-deficiency anemia*
Anemia
Nursing Process- Interventions
- Instruct the pt to take liquid iron through a straw to avoid staining tooth enamel
- Oral forms should be taken between meals for maximum absorption but may be taken with meals if gastrointestinal distress occurs
- Oral forms should be given with juice but not with milk or antacids
- Pts should be encouraged to eat foods high in iron and folic acid
Triglycerides
- one of the primary forms of lipids in the blood*
- Triglycerides are energy source stored in adipose tissue
- water-insoluble fats that must be bound to apolipoproteins, which are specialized lipid-carrying proteins
- Lipoprotein is the combination of triglyceride or cholesterol with apolipoprotein
Cholesterol
- one of the primary forms of lipids in the blood*
- Cholesterol is used to make steroid hormones, cell membranes and bile acids
- water-insoluble fats that must be bound to apolipoproteins, which are specialized lipid-carrying proteins
- Lipoprotein is the combination of triglyceride or cholesterol with apolipoprotein
Very low density Lipoproteins
- produced by the liver
- They transport endogenous lipids to peripheral cells
Intermediate density lipoproteins
- can be low density (LDL) or high density (HDL)
- These are responsible for “recycling” cholesterol
- HDL is the “good cholesterol”
- LDL is the “bad cholesterol”
Risk of CAD & cholesterol levels correlation
The risk of CAD in pts with cholesterol levels of 5.2mmol are 3-4x greater than pts with levels less than 4.0mmol/L
Five Established Classess of Antilipemic Drugs
- Hydroxymethylglutaryl-coenzyme A (HMG-CoA) reductase inhibitors (STATINS)
- Bile Acid Sequestrants
- Niacin (Niaspan, nicotinic acid)
- Fibric Acid Derivatives
- Cholesterol Absorption Inhibitor
Hydroxymethylglutaryl-coenzyme A (HMG-CoA) reductase inhibitors
(STATINS)
○ FIRST LINE therapy for hypercholesterolemia (elevated LDL)
○ Reduces plasma concentrations of LDL cholesterol by 30-40%
○ Decreases plasma triglycerides by 10-30%
○ Increases HDL cholesterol by 2-15%
○ It is dose dependent
Hydroxymethylglutaryl-coenzyme A (HMG-CoA) reductase inhibitors (STATINS)
Most potent LDL reducers:
- pravastatin sodium
- simvastatin (Zocor)
- atorvastatin (Lipitor)
- fluvastatin sodium (Lescol)
- rosuvastatin calcium (Crestor)
- lovastatin
Hydroxymethylglutaryl-coenzyme A (HMG-CoA) reductase inhibitors (STATINS)
Action
○ Inhibits HMG-CoA reductase enzyme, which is used by the liver to produce
cholesterol
○ It lowers the rate of cholesterol production by increasing the amount of LDL
receptors in the liver
Hydroxymethylglutaryl-coenzyme A (HMG-CoA) reductase inhibitors (STATINS)
Adverse effects
○ Mild, transient GI disturbances (constipation)
○ Rash
○ Headache
○ Myopathy (muscle pain), possibly leading to rhabdomyolysis, a serious condition
○ DO NOT USE IN PTS WITH ELEVATED LIVER ENZYMES OR LIVER DISEASE (Cirrhosis/Hepatitis)
Hydroxymethylglutaryl-coenzyme A (HMG-CoA) reductase inhibitors (STATINS)
contraindicated in pts with
IN PTS WITH ELEVATED LIVER ENZYMES OR LIVER
DISEASE (Cirrhosis/Hepatitis)
Rhabdomyolysis
- A breakdown of muscle protein**
- Myoglobinuria: urinary elimination of the muscle protein myoglobin***
- It can lead to acute kidney injury and even death
- It can be reversible when recognized early by discontinuing the drug
- Instruct pt to report any signs of toxicity, including muscle soreness or changes in urine
color (it is TEA-COLORED) - Avoid grapefruit juice*
- Higher risk in individuals over 65 years, renal disease, some medications,
hypothyroidism
most commonly used drugs in STATIN class
simvastatin (Zocor) & atorvastatin (Lipitor)
simvastatin (Zocor) & atorvastatin (Lipitor)
- Lowers total and LDL cholesterol levels as well as triglyceride levels and raises “good”
cholesterol (HDL) - Dosed once daily, usually with the evening meal or at bedtime to correlate with diurnal
rhythm
Bile Acid Sequestrants
- cholestyramine resin (Olestyr)
- colestipol hydrochloride
- colesevelam
Bile Acid Sequestrants
Action
○ Prevents resorption of bile acids from small intestine
○ Bile acids are necessary for absorption of cholesterol
○ Type II hyperlipoproteinemia
○ May be used along with ‘statins’
Bile Acid Sequestrants
Adverse effects
○ Constipation
○ Heartburn
○ Nausea
○ Belching
○ Bloating
○ May cause mild increases in triglyceride levels
○ These effects tend to disappear over time
interventions:
○ Increasing dietary fibre intake or a fibre supplement (Metamucil)
○ Increasing fluid inake
Niacin (Niaspan, nicotinic acid)
○ Vitamin B3
○ Lipid-lowering properties requires much higher doses than when used as a vitamin
○ It is effective, inexpensive, and it is often used in combination with other lipid-lowering drugs
○ Reduces the metabolism or catbolism of cholesterol and triglycerides
○ It is effective in lowering triglyceride, total serum cholesterol, and LDL
cholesterol levels
○ Increases HDL levels
○ Effective in the treatment of types IIa, IIb, III, IV, and V dyslipidemia
Niacin (Niaspan, nicotinic acid)
Adverse effects
○ Flushing, caused by histamine release
○ Pruritus
○ GI distress
Fibric Acid Derivatives
○ Also known as fibrates
○ Effective in the treatment of types III, IV, and V hyperlipidemias
○ They can decrease the triglyceride level and increase the HDL cholesterol level by
as much as 25%**, but not as strong as ‘statin’
○ It can be given with a ‘statin’, which increases risk of myositis, myalgia, rhabdomyolysis
Fibric Acid Derivatives medications
■ bezafibrate
■ gemfibrozil (Lopid) ■ fenofibrate (Tricor)
Fibric Acid Derivatives
Action
○ Works by activating lipoprotein lipase, which breaks down cholesterol
○ Suppresses the release of free fatty acid from adipose tissue, inhibits the synthesis
of triglycerides in the liver, and increases the secretion of cholesterol in the bile
Fibric Acid Derivatives
Adverse effects
○ Abdominal discomfort, diarrhea, nausea
○ Blurred vision, headache
○ Increased risk of gallstones*
○ Prolonged prothrombin time
○ Increased enzyme levels perhaps shown by liver studies
Cholesterol Absorption Inhibitor
ezetimibe (Ezetrol)
○ Inhibits absorption of cholesterol and related sterols from the small intestine
○ Results in reduced total cholesterol, LDL cholesterol, apolipoprotein B, and triglyceride levels
○ Also increases HDL cholesterol levels
○ It is often combined with a statin drug
○ It can be used as monotherapy
Herbal Products: Garlic
- Used as an antispasmodic, antiseptic, antibacterial, antiviral, antihypertensive, antiplatelet, and lipid reducer
- Possible interactions with warfarin, diazepam, and protease inhibitors
- May enhance bleeding when taken with NSAIDs
Garlic Adverse effects
- Dermatitis
- Vomiting & Diarrhea
- Anorexia
- Flatulence
- Antiplatelet activity
Herbal Products: Flax
- Used for atherosclerosis, hypercholesterolemia, hypertriglyceridemia, GI distress,
menopausal symptoms, bladder inflammation - May cause diarrhea and allergic reactions
- Possible interactions with antihyperglycemic drugs, anticoagulant drugs
Herbal Products: Omega-3 Fatty Acids
- Fish oil products
- Used to reduce cholesterol
- May cause rash, belching, allergic reactions
- Potential interactions with anticoagulant drugs
- Contraindicated in pregnancy*
Liver Enzymes
- LFT means liver function test, which assesses multiple liver enzymes
- Other liver enzymes that are tested include: ALT, SCPT, LDH, GGT, CPK, AST
Antilipemic
Nursing Process - Assessment
- Assess dietary patterns, exercise level, weight, height, VS, tobacco and alcohol use,
family hx - Contraindications include biliary obstruction, liver dysfunction, and active liver dysfunction
- Monitor for adverse effects, including increased liver enzymes or signs of myalgias
- Ensure pts report GI upset, constipation, abnormal or unusual bleeding, and yellow discoloration of the skin
Antilipemic
Nursing Process - Interventions
- Patients on long term therapy may need supplemental fat-soluble vitamins (A,D,E,K) with Bile Acid Sequestrants
- Counsel pt concerning diet and nutrition on an ongoing basis
- Instruct pt on proper procedure for taking the medication
- Start a low initial dose of niacin and gradually increase to minimize adverse effects
- Small doses of aspirin or NSAIDs may be taken 30 minutes before niacin to minimize cutaneous flushing
- Inform pts that medications may take several weeks to show effectiveness
proper procedure for taking antilipemic medication
- Powder must be taken with a liquid, mixed thoroughly but not stirred, and never taken dry
- Other medications should be taken 1 hour before or 4-6 hours after meals to avoid interference with absorption
Hemostasis
- Any process that stops bleeding
- Coagulation is hemostasis that occurs because of the physiological clotting of blood
- Complex relationship between substances that promote clot formation and either inhibit
coagulation or dissolve a formed clot - Clots are usually absorbed into the body
- Anticoagulants are used as prophylaxis for clotting
Thrombus
- medical term for a blood clot
- An aggregation of platelets, fibrin clotting factors and the cellular elements of the blood that is attached to the interior wall of a vein or artery
Embolus
- thrombus that moves through blood vessels
- If an embolus lodges in a coronary artery, it causes a myocardial infarction
- If it obstructs a brain vessel, it causes a stroke (cerebrovascular accident)
- If it travels to the lungs, it is a pulmonary embolus
- If it travels to a vein in the leg, it is a deep vein thrombosis (DVT)
- Collectively, these complications are called “thromboembolic events”
Coagulation System
- “Cascade”
- Each activated factor serves as a catalyst that amplifies the next reaction
- Result is fibrin, a clot-forming substance
- Intrinsic pathway and extrinsic pathway
Anticoagulant action
○ Inhibit the action or formation of clotting factors
○ Prevents clot formation
Antiplatelet drug action
○ Inhibits platelet aggregation
○ Prevents platelet plugs
■ Thrombolytic agents (breaks down formed clots)
■ Antifibrinolytics agents (promotes blood coagulation and clot formation)
Anticoagulants
- Also known as antithrombotic drug
- It has no direct effect on a blood clot that is already formed
- Prevents intravascular thrombosis by decreasing blood coagulability
- Used prophylactically to prevent:
Clot formation (thrombus)
Embolus (dislodged clot)
Heparin
- 3 types
- anticoagulant
○ Action: inhibits clotting factors IIa (thrombin), Xa, and IX
○ Unfractionated heparin: heparin sodium (another type of heparin, given as infusion)
○ Low-molecular-weight heparins (predictable course of events that requires less monitoring) - IV or SC
Unfractionated Heparin Sodium
○ Large molecule that is derived from pig lungs/intestinal mucosa
○ It is available in 10-10,000 units/mL
○ Frequent laboratory monitoring for bleeding times such as aPTT (how long it takes blood to clot in seconds)
○ When heparin is used therapeutically (for treatment), continuous IV infusion
■ Measurement of activated partial thromboplastin time (aPTT), which is usually every 6 hours is necessary
■ PTT is usually 25-35 seconds, when the pt is on heparin we want the PTT to be 45-70 seconds
○ Weight-based protocol; how much heparin to give is determined based on weight
Low-Molecular-Weight Heparins (LMWHs)
○ Synthetic smaller molecular structure (fractionated)
○ More predictable anticoagulant response; more specific for activated factor X
○ Frequent lab monitoring of bleeding times is NOT NEEDED, NO NEED FOR
PTT LAB
Heparin Flushes
- Heparin Leo
- Small vial of aqueous heparin IV flush solution
- Risk of the development of heparin-induced thrombocytopenia has caused most institutions to use 0.9% normal saline as a flush for heparin-lock IV ports**
- Heparin flushes (100 units/mL) are still used for central catheters
Anticoagulants
● Warfarin (Coumadin)
○ Inhibits vitamin K synthesis by bacteria in the gastrointestinal tract
○ Action: inhibits vitamin K dependent clotting factors, II, VII, IX, and X which are
normally synthesized in the liver
○ Final effect is the prevention of clot formation
○ It is most commonly prescribed as an oral anticoagulant
○ Monitoring of prothombin time (PT) and international normalized ratio (INR) is
necessary
NORMAL INR
0.8-1.2 seconds
WARFARIN INR
3.5 seconds depending on the indication for use
of the drug***
Considerations with Warfarin
○ Dietary considerations
○ Variations in certain genes
○ Age considerations
○ Maintenance dose determined by the INR
○ Natural health product cautions
Anticoagulants: Indications
- Used to prevent clot formation in certain settings in which clot formation is likely - MI
- Unstable angina
- Atrial fibrillation
- Indwelling devices, such as mechanical heart valves
- Conditions in which blood flow may be slowed and blood may pool
Anticoagulants: Contraindications
- Drug allergies
- Acute bleeding process or high risk of an occurrence
- Warfarin is strongly contraindicated in pregnancy
- Low-molecular-weight heparins are contraindicated in pts with an indwelling epidural catheter, as there is risk of epidural hematoma
Low-molecular-weight heparins are contraindicated in pts with
an indwelling epidural
catheter, as there is risk of epidural hematoma
Anticoagulants: Adverse Effects
- Bleeding
Risk increases with increased dosages
May be localized or systemic - Herparin-induced thrombocytopenia
- Nausea
- Vomiting
- Abdominal cramps
- Thrmbocytopenia
Warfarin Adverse Effects
- Bleeding
- Lethargy
- Muscle pain
- Skin necrosis
- “Purple toes” syndrome
Toxic Effects of Heparin
Symptoms: hematuria, melena (blood in the stool), petechiae, ecchymoses, gum or
mucous membrane bleeding
Interventions for Heparin toxicity
- Aimed at reversing the underlying cause
- Stop the drug IMMEDIATELY
- IV protamine sulphate: 1mg can reverse the effects of 100units of heparin
- 1mg for each mg of low-molecular-weight-heparin given**
Heparin toxicity antidote
IV protamine sulphate
Toxic Effects of Warfarin (interventions)
- Vitamin K can help body return to normal coagulation
- When vitamin K is given, warfarin resistance will occur for up to 7 days
- Severe bleeding: transfusions of human plasma or clotting factor concentrates
- IV vitamin K: risk of anaphylaxis: Dilute and give over 30 minutes to diminish risk - Common to give the injectable form orally
- Discontinue the drug
- May take 36 to 42 hours before the liver can resynthesize enough clotting factors to reverse the warfarin effects
Antiplatelet Drugs
Prevents clot formation by inhibiting platelet adhesion at the beginning of the cascade
- Acetylsalicylic acid (ASA) 81mg-325mg
- clopidogrel bisulfate (Plavix)
Antiplatelet Drugs
● Mechanism of Action
○ Affects the normal function of platelets to prevent platelet adhesion to the site of blood vessel injury
Antiplatelet Drug Indications
○ Stroke, TIA, post MI thrombo prevention
○ Some antiplatelets used in conjunction with anticoagulant Warfarin as a prophylaxis for CVA, PE, and DVT
ASA Side Effects
○ Thrombocyopenia
○ Agranulocytosis
○ Anemia
○ GI bleeding
○ Diarrhea
○ Nausea
○ Vomiting
Clopidrogel Side Effects
○ Chest pain
○ Abdominal pain
○ Diarrhea
○ Epistaxis
○ Headache
○ Dizziness
○ Fatigue (flu like symptoms)
Nursing Process & Heparin
- IV doses are usually double-checked with another nurse high alert
- Ensure that SC doses are given SC, not IM
- SC doses should be given in areas of deep SC fat, and sites should be rotated
- Do not give SC doses within 5cm of the umbilicus, abdominal incisions, open wounds, scars, drainage tubes, stomas, or areas of bruising/oozing
- IV doses may be given by bolus or IV infusions
- Anticoagulant effects are seen immediately
- Laboratory values are done daily to monitor coagulation effects (aPTT)
- Protamine sulphate is the antidote in case of excessive anticoagulation
Nursing Process & Low-Molecular-Weight Heparins
- Given SC in the abdomen
- Rotate injection sites
- Protamine sulphate can be given as an antidote in case of excessive anticoagulation
Nursing Process & Warfarin (Coumadin)
- May be started while the pt is still on heparin until PT/INR levels indicate adequate anticoagulation (cross-over therapy or bridging therapy)
- Full therapeutic effect takes several days
- Monitor PT/INR regularly, keep follow up appointments
- Antidote is Vitamin K
- Herbal products may have potential interactions; increased bleeding may occur: Garlic
Capsicum pepper
Ginger
St. John’s wort
Anticoagulants and Antiplatelet: Patient Education
- Importance of regular lab testing
- Signs of abnormal bleeding
- Measures to prevent bruising, bleeding, and tissue injury
- Avoiding foods high in Vitamin K (tomatoes, dark leafy green vegetables) on Warfarin
- Consulting the physician before taking other medications, including herbals
