Week 9- Cardiac Glycosides, Antianginal Agents, Anticoagulants Flashcards
What is congestive heart failure (HF)?
a condition in which the body fails to effectively pump the blood throughout the body
What is the primary treatment for HF?
- involves helping the heart muscles to contract more efficiently to bring the system back into balance
- Vasodilators (ACEI and Nitrates)
- Diuretics
- Beta-Adrenergic agonists
What are some examples of underlying problems in HF?
- atherosclerosis or cadiomyopath (damage to muscles)
- hypertension or valvular diseases (heart has to work too hard)
- congenital cardiacdefects (abnormal structure)
What are some causes of HF?
- Coronary Artery Disease (CAD)
- Cardiomyopathy
- Hypertension
- Valvular Heart Disease
How do vasodilators (ACEI and Nitrates) work to treat HF?
- decrease workload of overworked cardiac muscles
How do diuretics work to treat HF?
- decrease blood volume, which decreases venous return and BP
How do Beta-Adrenergic Agonists work to treat HF?
- stimulate the beta-receptors in the SNS, increasing calcium flow into the myocardial cells, and causing increased contraction
What are the effects of cardiac glycosides?
- Increased force of myocardial contraction
- Increased cardiac output and renal perfusion
- Increased urine output and decreased blood volume
- Slowed heart rate
- Decreased conduction velocity through the AV node
What are the actions of cardiac glycosides?
- Increases intracellular calcium, allows more Ca to enter the myocardial cells during depolarization
- positive notrpic efefct, increases renal perfusion with a diuretic effect and decreases in renin release, and slowed conduction through the AV node
What are cardiac glycosides indicated for?
- HF
- atrial fibrillation
What are the pharmacokinetics of cardiac glycosides?
- Rapidly absorbed and widely distributed throughout the body
- Primarily excreted unchanged in the urine
What are the adverse effects of cardiac glycosides?
- Headache, weakness, drowsiness, and vision changes
- GI upset and anorexia
- Arrhythmia development
What is the most common complaint of cardiac glycosides?
headaches
What are the contraindications and cautions of cardiac glycosides?
Contraindications
- Allergy
- Ventricular tachycardia or fibrillation
- Idiopathic hypertrophic subaortic stenosis
- Acute MI, renal insufficiency, and electrolyte abnormalities
Caution
- Pregnancy and lactation
- Pediatric and geriatric patients
What are cardiac glycosides drug to drug interactions?
- Verapamil, amiodarone, quindine, quinine, erythromycin
- potassium losing diuretics
- cholestyramine, charcoal, colestipol, bleomycin, cyclopisphamide
What is the prototype of cardiac glycosides?
digoxin (Lanoxin)
increase intracellular calcium causing increased force of contraction, better renal perfusion and slower HR
What is digoxin the prototype of?
cardiac glycocides (increase intracellular calcium causing increased force of contraction, better renal perfusion and slower HR)
What is the main concern of digoxin (Lanolin)?
slowing HR too much
Does digoxin have a narrow therapeutic window?
yes
What needs to be monitored when patients are on digoxin?
- drug levels
- electrolytes (potassium especially)
- BP, apical pulse, heart sounds, breath sounds; weight, intake and output (to monitor for edema)
- electrocardiogram
- serum lab: potassium (decreased potassium increases its toxicity), sodium, magnesium, calcium, renal and liver function
- monitor therapeutic and adverse effects
What are normal potassium levels?
3.5-5 mmol/L
What is the most important to remember with digoxin?
Before giving digoxin take apical pulse for 1 min; only give if it is in-between 60-120 bpm, otherwise hold dose and notify prescriber
Why are signs and symptoms of digoxin toxicity?
- anorexia, nausiea, vomiting, diarrhea or visual disterbances (blurred vision seeing green or yellow halos)
What should be avoided on digoxin?
- high fibre (fibre binds to digitalis)
What patient teaching is needed for those taking digoxin?
- avoid fibre
- report weight gain of 1 kg or more in one day
- signs and symptoms of toxicity
What therapeutic effects of digoxin are you monitoring for?
- increased urinary output
- decreased edema, SOB, dyspnea, crackles, fatigue
- resolving or paroxysmal nocturnal dyspnea
- improved peripheral pulse, skin colour, temp
Define atheroma.
fatty tumour in the intima of the heart vessels
Define atherosclerosis.
narrowing of the heart vessels
Define angina pectoris.
suffocation of the chest wall
Define myocardial infarction.
cells in the myocardium become necrotic and die
What are 4 types of CAD?
- atheromas
- atherosclerosis
- angina pectoris
- myocardial infarction
What are 3 types of angina?
- stable angina (effort angina or classic angina)
- unstable angina (pre-infarction)
- Prinzmetal’s angina (vasospastic)
What is stable angina?
- no damage to the heart muscle
- basic reflexes surrounding the pain restores blood flow
What is unstable angina?
episodes of ishemia occur
What is Prinzmetal’s angina?
- caused by spasm of the blood vessels, not just by vessels narrowing
What is the action of anginas?
- improve blood delivery to the heart muscle by dilating blood vessels; improves delivery
What are some types of anti- anginal medications
- Nitrates
- Beta-adrenergic blockers
- Calcium channel blockers
What is the action of nitrates?
acts directly on smooth muscle to cause relaxation and depress muscle tone
What are nitrates indicated for?
angina pectoris
What is the pharmacokinetics of nitrates?
- rapid absorption
- metabolized in the liver
- excreted in the urine
What is an example of nitrates?
- nitroglyseride
What are the contraindications and caution of nitrates?
CONTRAINDICATIONS - allergy - severe anemia - head trauma or cerebral hemorrhage - pregnancy and lactation CAUTIONS - hepatic or renal disease - hypotension, hypovolemia, and conditions that limit CO
When you cause vasodilation you have increased risk of…
hypotension
What are the adverse effects of nitrates?
- related to vasodilation and decrease in blood flow
- CNS- headach, dizziness, and weakness
- GI- N&V
- CV- hypotension
- misc.- flushing, pallor increased perspiration
What drug does nitrate react with?
heparin
What is important to inform patients taking nitroglycerin?
- HEADACHES are a common side effect, but they decrease as you continue to use the meds
- teach PROPER USE of SL route (do not chew or swallow, lie down do to risk of hypotension)
- proper topical use (rotate site, removal of old meds)
- FIZZLE or burn sensation is felt with SL form and it indicates it is still potent
- DO NOT EXPOSE to light, heat, moisture
- keep in ORIGINAL PACKAGING
- keep FRESH SUPPLY(open bottle only good for 3m)
- TOLERANCE
What is the prototype of nitrates?
nitroglycerine
What category of drug is nitroglycerin?
nitrates
What routes can nitroglycerin be given in?
- IV
- Sublingual
- Translingual spray
- Transmucosal tablet
- Oral SR
- Topical ointment
- Transdermal
What routs are recommended for anginal attacks of nitroglycerin?
spray, sublingual, IV
What are some important nursing implications?
- lots of patient teaching
- monitor VS frequently if using IV nitroglycerine
When anginal pain occurs the patient should…
- stop activity sit or lie down
- take SL tab and wait 5 min
- if no relief in 5 min, take a second SL tab
- after 3 tabs or 15min with no relief call 911
- do not drive yourself to the hospital
What is the action of beta blockers?
- block beta-adrenergic receptor blockers in the heart and kidneys, decreasing the influence of SNS of these tissues; decreases CO and the release of renin
What are beta blockers indicated for?
treat stable angina pectoris and hypertension, prevents reinfarction in MI patients; treats stable CHF
Are doses of beta blockers the same for those taking it for hypertension as for those taking them for angina?
dose is significantly higher for hypertension for angina
What are the pharmacokinetics of beta blockers?
absorbed by GI tract, undergoes hepatic metabolism, excreted in the urine
What are the contraindications and cautions of beta blockers (atenolol)?
CONTRAINDICATIONS - bradycardia - cardiogenic shock - asthma or COPD - pregnancy and lactation CAUTIONS - DM - PVD - thyrotoxicosis
What are the adverse effects of atenolol?
Related to the block of SNS
What drugs interact with atenolol?
clonidine
What is an off label use for beta blockers?
stage fright
What routes are used for atenolol?
oral and IV
What is atenolol?
a beta blocker
What are the nursing implications of patients taking beta blockers?
- monitor pulse rate daily (after taking med)
- dizziness or fainting should be reported (hypotension)
- constipation prevention
- never stop med abruptly (rebound hypertension)
- inform patients of long term effects (not meant for immediate relief of angina pain)
- combining with NSAIDs can lead to a decreased antihypertensive effect
What patient teaching is required about rebound hypertensive crisis?
Inform patients that these medications are for long-term prevention of angina, not for immediate relief
What do calcium channel blockers do?
Inhibit the movement of calcium ions across the membranes of myocardial and arterial muscle cells, altering the action potential and blocking muscle cell contraction
What are calcium channel blockers indicated for?
- hypertension
- angina
What are the pharmacokinetics of calcium channel blockers?
Well absorbed
Metabolized in the liver
Excreted in the urine
What are the contraindications of calcium channel blockers/
- allergy
- renal or hepatic dysfunction
- pregnancy or lactation
What are the adverse effects of CCB?
Hypotension Cardiac arrhythmias GI upset Skin reactions Headache
What reaches with calcium channel blockers?
vary with each drug
What is the prototype of calcium channel blockers?
diltiazem
What is diltiazem?
calcium channel blocker
What is thromboembolic disorder?
Conditions that predispose a person to the formation of clots and emboli
What is hemorrhagic disorder?
disorder which excess bleeding occurs
What are 2 blood disorders?
thromboembolic disorder
hemorrhagic disorder
What is the action of anticoagulants?
interfere with the clotting cascade and thrombin formation
What is the action of anti platelet drugs?
alter the formation of platelet plug
What do thrombolytic drugs do?
break down the thrombus that has been formed
If you have an embolism what drug would you use to break up the clot?
- thrombolytic drugs
Which drug inhibits the platelet adhesion and aggregation by blocking receptor sites on the platelet membrane?
antiplatelet
What are anti platelet drugs indicated for?
- reduction of risk of recurrent TIAs or strokes
- reduce death or nonfatal MI
- MI prophylaxis
- anti-inflammatory, analgesic and antipyretic
What are the pharmacokinetics of anti platelet drugs?
- Well absorbed and bound to plasma proteins
- Metabolized in the liver and excreted in the urine
What are the contraindications and cautions of anti platelet drugs?
CONTRAINDICATIONS
- allergy, pregnancy and lactation
CAUTIONS
- bleeding disorders, recent surgery, closed-head injury
What are the adverse effects of anti platelet meds (aspirin)?
- bleeding
- headache, dizziness, and weakness
- GI distress
What re the drug interactions to watch for?
another drug that affects blood clotting
What kind of drug is aspirin?
antiplatelet
What are anticoagulants used for?
prophylactically to prevent…
- clot formation (thrombus)
- an embolism
In preventing clot formation what do anticoagulants also prevent?
- stroke
- MI
- deep vein thrombosis (DVT)
- pulmonary embolism
What are some signs of deep vein thrombosis (DVT)?
inflamed, hot and red (usually in the calf)
What are anticoagulants indicated for?
prevention of clot formation in settings where clots are likely to form
- atrial fibrillation
- indwelling devices (mechanical heart valves)
- major orthopaedic surgery
Why would heparin be given to someone with mechanical heart valves?
- slots tend to form around implanted devices
What kind of drugs are heparin (generic) and warfarin (Coumadin)?
anticoagulants
What is warfarin’s indication?
maintain state of anticoagulation when a patient is susceptible to potentially dangerous side effects
What is heparin’s action
inhibits the conversion of prothrombin to thrombin
What route is warfarin given?
PO
What route is heparin given?
IV or SC
What is the action of anticoagulants?
interfere with the normal cascade of events involved in the clotting cascade
Are the pharmacokinetics the same for all anticoagulants?
no they differ
What are contraindications for anticoagulants?
CONTRAINDICATIONS
- allergy
- conditions that could be compromised by increased bleeding tendencies
- pregnancy
- renal and hepatic disorders
CAUTIONS
- CHF, throtoxicosis, senility or psychosis
What is the antidote for warfarin?
vitamin K
What is thrombocytopenia?
low platelet levels
Warfarin is strongly contraindicated for what?
pregnancy
What are the adverse effects of anticoagulants?
- thrombocytopenia (low platelet levels)
- GI: N&V, abdominal cramps
- hepatic dysfunction
- alopecia, dermatitis, bone marrow suppression, prolonged and painful erection
What are the drug to drug interactions of anticoagulants like heparin and warfarin?
- Heparin and oral anticoagulants, salicylates, penicillins, or cephalosporins
- Heparin and nitroglycerine
- Warfarin – Number of documented interactions
What are the nursing interventions of heparin?
- DOUBLE CHECK DOSE by another nurse
- ensure that SC doses are given SC not IM
- SITE should be ROTATED and in an area of deep fat (abdomen)
- DO NOT give heparin within 5 cm of umbilicus, abdominal incisions, open wounds, scars or drainage tubes, stomas
- DO NOT aspirate or massage site (may cause hematoma formation)
- IV (bolus or infusion)
- Anticoagulant EFFECTS IMMEDIATELY
- lab values done daily (aPPT)
- antidote close
What does aPPT stand for?
activated partial thromboblastin time (lab test of heparin)
What is the antidote for heparin?
Protamine sulfate
How fast are the effects of heparin seen?
IV- immediately
SC- 20-60 min
How long does it take for warfarin to reach therapeutic levels?
3 days
What are the nursing implication of warfarin sodium?
- warfarin may be started while patient is on heparin until PT/INR levels indicate adequate anticoagulation
- monitor PT/INR reg (follow up appointments)
- antidote vitamin k
- dietary restriction
- leafy greens and fruits and veg (things high in vitamin k)
What are low molecular weight heparins?
- Inhibit thrombus and clot formation by blocking factors Xa and Iia
- fewer systemic adverse effects
- block angiogenesis
- indicated for specific uses in the prevention of clot formation after certain surgeries or bed rest
- do not need frequent blood monitoring
- SQ
- Prevention or management of thromboembolic disorders associated with surgery or ischemic complications of unstable angina and MI
- as effective as IV heparin
What are some examples of LMWH?
enoxaparin (Lovenox)
dalteparin (Fragmin)
What is the antidote for LMWH
protamine sulfate (same as heparin)
