Cardiovascular System Flashcards
(155 cards)
1
Q
positive iontropic drugs do what to the heart (cardiac glycosides)
A
increase the force of the muscle contraction
(used to treat heart muscle failure)
Ex: Digoxin
2
Q
what are cardiac glycosides used for
A
commonly used in the treatment of heart failure and to control atrial fibrillation or flutter
3
Q
cardiac glycoside mechanisms of action are
A
- increase muscle contractility
- change the electrical conduction properties of the heart
- result in resudced heart rate and improved cardiac efficiency
4
Q
what are the drug effects of cardiac glycosides
A
positive inotropic (modify the speed or contraction of muscle) effect: Increase in force and velocity of myocardial contraction (without an increase in oxygen consumption)
negative chrontropic (change the heart rate) effect: reduced heart rate
negative dromotropic (conduction speed in the AV node) effect: decreases the autmoatic response at SA node, decreases AV nodal conduction, and other effects
5
Q
What are some of the drug effects that you would notice with cardiac glycosides
A
- Increased stroke volume
- Reduction in heart size during diastole
- Decrease in venous blood pressure (BP) and vein engorgement
- Increase in coronary circulation
- Promotion of diuresis due to improved blood circulation
- Palliation of exertional and paroxysmal nocturnal dyspnea, cough, and cyanosis
6
Q
What would you use cardiac glycosides for
A
heart failure
atrial fibrillation/flutter
7
Q
What are some of the contraindications of cardiac glycosides
A
- know drug allergy
- ventricular tachycardia
- subaortic stenosis
8
Q
When using the cardiac glycoside Digoxin, what do you need to monitor for
A
it has a very narrow therapeutic window
drug levels must be monitored
monitor low potassium levels this increases the toxicity of digoxin
monitor electrolyte levels
9
Q
What are some of the side effects in the body that could occur from using the cardiac glycoside Digoxin
A
CV: dysrhythmias
CNS: headaches, fatigue, confusion
EENT:halo vision, flickering lights
GI: nausea, vomiting, diarrhea
10
Q
What do you use to reverse Digoxin toxicity
A
Digibind
11
Q
What are some predisposing factors that could put someone at risk for Digoxin toxicity
A
- low potassium levels
- having a pacemaker
- excessive calcium
- advanced age
12
Q
As nurses what needs to be done prior to and during administration of positive inotropic drugs
A
- assess history, allergies and contraindications
- assess: bp, apical pulse (for 1 minute) if loer than 60 or greater than 120 hold dose and notify prescriber, heart and breath sounds, weight, I & O, ECG, labs
- check dosage forms carefully, and follow instructions for giving
- avoid giving digoxin with high-fibre foods (fibre binds with digitalis)
- patients should report immediately a weight gain of 1 kg or more in 1 day or 2 kg or more in 1 week
- monitor for therapeutic effects
*Increased urinary output
*Decreased edema, shortness
of breath, dyspnea, crackles,
fatigue - resolving of paroxysmal
nocturnal dyspnea (severe
SOB and coughing at night
usually while sleeping) - improved peripheral pulses, skin
colour, temperature - monitor for adverse effects
13
Q
What are 2 primary forms of lipds in the blood
A
triglycerides and cholesterol
14
Q
What is another name for HMG-CoA reductase inhibitors
A
Statins (antilipemics)
Ex. crestor, zocor,lipitor
15
Q
What is the mechanism of action for statins
A
used to lower cholesterol levels by inhibiting the enzyme HMG-CoA reductase, which plays a central role in the production of cholesterol in the liver
16
Q
What are statins used for
A
hypercholesterolemia
17
Q
What are the contraindications for using statins
A
- know drug allergy
- if you are pregnant
- liver disease or elevated liver enzymes
18
Q
As nurses what needs to be monitored or assessed prior to and during administration of statin drugs
A
Obtain baseline liver function studies
Patients on long-term therapy may need supplemental fat-soluble vitamins (A, D, K)
Monitor for adverse effects, including increased liver enzyme studies
Monitor for therapeutic effects
19
Q
What are some of the adverse effects of statins
A
Mild, transient gastrointestinal (GI) disturbances
Rash
Headache
Myopathy (muscle pain), possibly leading to the serious condition rhabdomyolysis (breakdown of muscle fibers)
Elevations in liver enzymes or liver disease
20
Q
What can statins have interactions with that may cause unwanted effects
A
Oral anticoagulants Oral antidiabetic drugs erythromycin insulin Niacin Grapefruit juice
21
Q
When dealing with hypertension what drug categories are available to use
(there are 6)
A
- adrenergics
- ACE inhibitors
- ARBs
- calcium channel blockers
- diuretics
- vasodilators
22
Q
What are the 5 subcategories of adrenergic drugs
A
- centrally and peripherally acting adrenergic neuron blockers
- centrally acting a2 receptor agonists
- peripherally acting a1 receptor blockers
- peripherally acting b receptor blockers both cardioselective and nonselective
- peripherally acting dual a1 and b receptor blockers
23
Q
What is mechanism of action for centrally acting a2 receptor agonists (agonists stimulate a reaction)
A
- reduces renin (protein in the kidneys that promotes the production of the protein angiotensin) activity in the kidneys
- decreases norepinephrine production
- results in decreased blood pressure
24
Q
What is the mechanism of action for peripherally acting a1 blockers/antagonists (inhibitors)
A
- blocks the a1 adrenergic receptors
- includes doxazosin (Cardura) and prazosin (Minipress)
- decreases blood pressure
25
What is the mechanism of action for the peripherally acting b blockers both cardioselective and nonselective
- reduces bp by decreasing the heart rate through b1 receptor blockade
- reduces secretion of renin
- reduces peripheral vascular resistance
- decreases bp
26
What is the mechanism of action of peripherally acting a1 and b receptors blockers
- blocks the a1 adrenergic receptor
* reduces heart rate (b receptor blockade)
* vasodilation (a1 receptor blockade)
- one drug is carvedilol
- decreases bp
27
What are centrally acting a2 receptor agonists used for
- hypertension
| - glaucoma
28
What are peripherally acting a1 receptors agonists used for
- hypertension
- relief of benign prostatic hypertrophy
- mgme of severe heart failure when used with glycosides and diuretics
29
What are some contraindications for adrenergics
- drug allergy
- acute heart failure
- asthma
- colitis
30
What are some of the most common side effects of adrenergic drugs
- dry mouth
- drowsiness
- constipation
- orthostatic hypotension
31
What are ACE inhibitors used for
- heart failure
| - hypertension
32
What is the mechanism of action for ACE inhibitors
*Renin–angiotensin–aldosterone system
-stops the angiotensin-converting enzyme
from converting angiotensin I to
angiotensin II
(FYI - angiotensin II is a vasoconstrictor)
*Aldosterone stimulates water and sodium resorption
-this increases blood volume, cardiac
preload increases and bp increases
33
What are ACE inhibitors indicated for
-hypertension
-heart failure
-to slow the progression of left ventricular
hypertrophy after an MI (cardioprotective)
-renal protective in pt's with diabetes
(Note - drug of choice for diabetics and hypertensive patients with heart failure)
34
What is the suffix on the name of the drugs associated with ACE inhibitors
"prils"
Ex: captopril, enalapril,quinapril
35
What are some contraindications for ACE inhibitors
```
drug allergy
lactating women
children
bilateral renal artery stenosis
hyperkalemia
```
36
What are some side effects of ACE inhibitors
fatigue
headache
dizziness
mood changes
(Note - first dose may have a hypotensive effect)
37
What are the possible drug to drug interactions that can occur with ACE inhibitors
NSAIDs can reduce the effectiveness of the antihypertensive effect
if taking lithium this could result in lithium toxicity
if taking potassium supplements and potassium sparing diuretics this may result in hyperkalemia
38
What is the main difference btween ACE inhibitors and ARBs
ARBs do not cause a dry cough like ACE inhibitors do
39
What is the mechanism of action for ARBs
- allows angiotensin I to be converted to angiotensin II but blocks the receptors from receiving angiotensin II
- blocks the vasoconstriction and the release of aldosterone
40
What is the suffix that ARB drug come with
"sartan"
Ex: losartan, valsartan
41
What are the indications for ARBs
-hypotension
-used as an adjunct for tx of heart failure
-used primarily in pt's that can't tolerate ACE
inhibitors
42
What are the contraindications for ARBs
drug allergy
pregnancy
lactation
43
What are some drug to drug interactions
phenobarbital
| cimetidine
44
What are some adverse side effects of using ARBs
- headaches
- upper respiratory infections
- dizziness
- diarrhea
45
What is the mechanism of action for calcium channel blockers
they cause smooth muscle relaxation by blocking calcium from its receptors. This prevents muscle contractions from happening
which in turn decreases vacular resistance and bp
46
What would you used calcium channel blockers for
- angina
- hypertension
- dysrhythmias
- migraine headaches
47
What do diuretics do in regards to the heart
- decrease preload
- decrease cardiac output
- decrease total peripheral resistance
(the overall effect is the workload of the heart is decrease and this in turn decreases bp)
48
Which diuretics are the most commonly prescribed for hypertension
thiazide diuretics
49
What is the mechanism of action for vasodilators
- directly relax arteriolar and venous smooth muscle
- decreased systemic vascular response,
- decreased afterload
- decreased peripheral vasodilation
50
What is the suffix that comes with the names of thiazide drugs
"ide"
Ex: hydralazine, sodium nitroprusside
51
What are vasodilator drugs indicated for
hypertension
52
What are some of the contraindications for vasodilators
```
drug allergy
hypotension
head injury
MI
CAD
```
53
What are some of the side effects that vasodilators have
```
dizziness
headache
anxiety
hypotension
bradycardia
```
54
As nurses what needs to be monitored or assessed prior to and during administration of vasodilator drugs
(there are 7, try to list 4)
- obtain health history
- head to toe physical
-assess for contraindications specific to
hypertensive drugs
-assess for conditions hat require caution when
using these drugs
- monitor for adverse effects
- monitor for therapeutic effect
- monitor bp throughout therapy
55
What are diuretics
drugs that accelerate the rate of urine formation (they remove sodium and water)
they cause arteriole dilation reducing fluid volume, plasma volume and cardia output
56
What are the different types of diuretics
loop diuretics (furosemide or Lasix)
potassium-sparing diuretics (spironolactone)
thiazide and thiazide like diuretics
(hydrochlorothiazide and metolazone)
57
What is the mechanism of action with loop diuretics
they work directly on the loop of henle in the kidney to stop chloride and sodium reabsorption
increase kidney prostaglandins resulting in dilation of blood vessels and reduced peripheral vascular resistance
58
When a person takes this drug what will happen
-there is a decrease in fluid volume which can cause:
reduced bp
reduced pulmonary vascular resistance
reduced system vascular resistance
reduced left ventricular end-diastolic pressure
-potassium and sodium loss
59
What are loop diuretics used for
- edema associated with heart failure
- control of hypertension
- hypercalcemia
60
What are some contraindications for loop diuretics
- drug allergy
- allergy to sulfonamide antibiotics
- severe electrolyte loss
61
What are some of the adverse effects on the body when taking a loop diuretic
```
CNS = dizziness, headache, tnnitus
GI = nausea, vomiting, diarrhea
HEMA = thrombocytopenia
META = hypokalemia, hyperglycemia
```
62
What is the mechanism of action for a potassium-sparing diuretic
- work in collecting ducts and distal convoluted tubules
- interfere with sodium–potassium exchange
- block the resorption of sodium and water usually induced by aldosterone
63
What is a potassium-sparing diuretic used for
- hypertension
- certain causes of heart failure
- hyperaldosteronism
64
What are the contraindications for potassium-sparing diuretics
- drug allergy
- hyperkalemia
- severe kidney failure or anuria
65
What are some of the adverse effects on the body when taking potassium-sparing diuretics
```
CNS = dizziness, headache
GI = cramps, nausea, vomiting
other = urinary frequency, weakness
```
66
What are a couple of adverse effects of taking spironolactone specifically
- amenorrhea
| - irregular menses
67
What are some drug to srug interactions for potassium-sparing diuretics
lithium
ACE inhibitors
potassium supplements
68
What is the mechanism of action for thiazide and thiazide like diuretics
inhibit tubular resorption of sodium, chloride, and potassium ions
act primarily in the distal convoluted tubule
result in excretion of water, sodium, and chloride, and potassium to a lesser extent
dilate the arterioles by direct relaxation
69
What are the effects of thiazide and thiazide like diuretics
lowered peripheral vascular resistance
depletion of sodium and water (and potassium)
70
What indications ae thiazide and thiazide like diuretics used for
hypertension
edema
heart failure d/t diastolic dysfunction
71
What are the contraindications for thiazide and thiazide like diuretics
drug allergy
anuria
severe kidney failure
72
What are some of the adverse effects on the body when taking thiazide and thiazide like diuretics
```
CNS = dizziness, headache
GI = anorexia, nausea
GU = impotence
INTEG = urticaria, photosensitivity
META = hypokalemia, hyperglycemia
```
73
What are some of the nursing things that as a nurse needs to be done prior to and during therapy
-perform a physical exam
-assess baseline fluid volume
I & O, weight
vital signs
electrolyte values
- assess for any contraindications
- monitor for adverse effects
- monitor for therapeutic effects
- monitor potassium levels
74
What are some teaching that nurses can give to patients regarding diuretic drugs
(there are several name 5)
-teach patients to maintain proper nutritional and fluid volume status
- teach patients to eat more potassium-rich foods when taking any but the potassium-sparing drugs, like:
- bananas, oranges, dates, raisins
- patients taking diuretics and digitalis should be taught to monitor for digitalis toxicity
- diabetics taking thiazide and/or loop diuretics need to monitor blood glucose
- teach patients to change positions slowly to prevent orthostatic hypotension
- encourage patients to return for follow-up visits and laboratory tests
- instruct patients to take in the morning can cause sleeplessness if taken at night
75
What are some teaching that nurses can give to patients regarding statin drugs
advise patients to take with meals to decrease GI upset
patient must be counselled concerning diet and nutrition on an ongoing basis
instruct on proper procedure for taking the medications
instruct patients to report persistent GI upset, constipation, abnormal or unusual bleeding, and yellow discoloration of the skin
76
What are some teaching that nurses can give to patients regarding statin drugs
-educate pt about taking medication
appropriately
-advise pt never to double dose if a dose is
missed
-advise pt to talk to doctor before stopping
medication
-advise pt about exercising regularly
-advise pt about making positive lifestyle
changes
-medication should be taken with food so that
absorption is more effective
77
What types of drugs (classifications) are used for angina
nitrates
calcium channel blockers
beta blockers
78
What is the therapeutic objective for antianginals
increase blood flow to the ischemic heart
decrease oxygen demand (or both)
minimize frequency of the attacks
improve pt's functional capacity
79
What is the mechanism of action for nitrates
cause vasodilation d/t relaxation of smooth muscles
has a potent dilating effect on coronary arteries
vasodilation results in reduced myocardial oxygen demand
nitrates cause dilation of both large and small coronary vessels
nitrates alleviate coronary artery spasms
80
What are nitrates used for
Rapid-acting forms:
-are used to treat acute anginal attacks
Long-acting forms:
-are used to prevent anginal episodes
81
What are some of the contraindications of nitrates
- drug allergy
- severe anemia
- hypotension
- severe head injury
82
What are some of the adverse effects of nitrates
headaches
tachycardia
postural hypotension
83
What are some drug to drug interactions for nitrates
Can produce additive hypotensive effects when taken with:
alcohol
beta blockers
calcium channel blockers
84
What are a couple of drug names that are indicated for angina
(drug names end "olol"
atenolol
metoprolol
propanolol
85
What is the mechanism of action for beta blockers
b1-adrenergic receptors on the heart are blocked
- decrease the heart rate, resulting in
- decreased oxygen demand
- decrease contractility
b-blockers block the harmful effects of catecholamines, thus improving the chances of survival after an MI
86
What do you use beta blockers for
angina
antihypertensive
cardiac dysrhythmias
cardioprotective effects
87
What adverse effects occur to the body systems using beta blockers
```
CV = bradycardia, hypotension, heart failure
META = altered glucose and lipids
CNS = dizziness, drowsiness, fatigue
OTHER = wheezing, dyspnea
```
88
What are some patient teaching that should be done by the nurse
monitor pulse rate daily and report any rate lower than 60 beats/min
Dizziness or fainting should also be reported
Constipation is a common problem, tell pt's to drink plenty of fluids and eat high fiber foods
beta blockers should never be abruptly discontinued d/t risk of rebound hypertensive crisis
89
What should be monitored by the nurse when a pt is on antianginals
monitor for adverse reactions (allergic reactions, heaache, dizziness)
monitor for therapeutic effect (relief from angina, decreased bp)
90
What is a common side effect of calcium channel blockers that the patient should be advised of by the nurse
Constipation is a common problem; instruct patients to take in adequate fluids and eat high-fibre foods
91
What is the common suffix used when dealing with calcium channel blocker medications
"ines"
92
What is the mechanism of action for calcium channel blockers
cause coronary artery vasodilation
cause peripheral arterial vasodilation
decreasing systemic vascular resistance
reduce workload of the heart
93
Why would you use calcium channel blockers
hypertension
| angina
94
What are some adverse effects of calcium channel blockers
```
hypotension
palpitations
tachycardia
bradycardia
constipation
```
95
Why should you not have grapefruit juice if you are taking calcium channel blockers
it reduces the metabolism of the medication
96
What are soem teaching points that should be given to a patient on nitroglycerin
- Instruct in proper technique and guidelines for taking sublingual (SL, transdermal etc) nitro for anginal pain
- Instruct never to chew or swallow the SL form
- Instruct that a burning sensation felt with SL forms indicates that the drug is still potent
Instruct patients to keep a fresh supply of nitroglycerin on hand; the drug loses its potency after about 3 months of the bottle having been opened
Instruct to keep meds away from moisture, light, heat, and cotton filler and to keep it in its original packaging
Monitor vital signs frequently during acute exacerbations of angina
A patient taking sublingual nitroglycerin who experiences chest pain should lie down to prevent or decrease dizziness and fainting that may occur due to hypotensionIf anginal pain occurs, the patient should:
*Stop activity and sit or lie down
*Take an SL tablet, and wait 5 minutes
*If no relief in 5 minutes, take a second
SL tablet
*If no relief in 5 minutes, take a third SL
tablet
*After three tablets, or 15 minutes, if no
relief of chest pain, call 911
Note: New recommendations are that if the patient is still having chest pain after 1 dose of sublingual nitroglycerin, he or she should immediately call 911
97
What are anticoagulants
prevent clot formation
98
What antiplatelet drugs
inhibit platelet aggregation
99
What are thrombolytics
these drugs breakdown exsisting clots
100
What are hemostatic (antifibrinolytic) drugs
these promote blood coagulation
101
If a blood clot has already formed will an anticoagulant have any affect on it
No
102
What is the mechanism of action for anticoagulants
- work on different points of the clotting cascade
- they do not destroy pre-exsisting clots
- they are use to prevent clot formation
103
By preventing clot formation what else are preventing from happening
stroke
MI
DVT
pulmonary embolism
104
What are some contraindications for anticoagulants
drug allergy
acute bleeding
deficiency of plateletsin the blood
(thrombocytopenia)
(Note- warfarin is strongly contraindicated in pregnancy)
105
What are some adverse effects when using anticoagulants
```
bleeding risks
nausea
vomiting
abdominal cramps
thrombocytopenia (lack of platelets)
```
106
How is heparin monitored (lab test)
activated partial thromboplastin times (aPTTs)
107
What is heparins antidote if needed
protamine sulfate
108
How is warfarin monitored (lab test)
```
prothrombin time (PT) and,
International Normalized Ratio (INR)
```
109
What is the antidote for warfarin
vitamin K
110
What do antiplatelet drugs do
prevent platelet adhesion
111
Which drugs are anti platelet drugs
aspirin (ASA)
| clopidogrel (Plavix)
112
What are the uses for anti platelet drugs
reduce risk of fatal and non fatal strokes
113
What are some contraindications for using antiplatelet drugs
drug allergy
active bleeding
thrombocytopenia
traumatic injury
114
What are some drug interactions with anti platelet drugs
```
aspirin
NSAIDS
clopidogrel
can cause an additive effect and increase
bleeding potential
```
115
What as a nurse should be done when administering heparin
Ensure that subcutaneous doses are given subcutaneously, not intramuscularly
Subcut doses should be given in areas of deep subcutaneous fat, and sites should be rotated
Do not give subcutaneous doses within 5 cm of: the umbilicus, abdominal incisions, open wounds, scars, drainage tubes, stomas
Do not aspirate subcut injections or massage injection site, may cause hematoma formation
Anticoagulant effects are seen immediately
Laboratory values are done daily to monitor coagulation effects (aPTT)
Monitor for therapeutic effects
Monitor for signs of excessive bleeding
Monitor for adverse effects, increased bp
headache, hematoma formation, hemorrhage, shortness of breath, chills, fever
116
What as a nurse should be done when administering warfarin
warfarin may be started while the patient is still on heparin until PT/INR levels indicate adequate anticoagulation
Full therapeutic effect takes several days
Monitor PT/INR regularly—keep follow-up appointments
```
Many herbal products have potential interactions—increased bleeding may occur
Capsicum pepper
Feverfew
Garlic
Ginger
Gingko
Ginseng
```
Monitor for therapeutic effects
Monitor for signs of excessive bleeding
Monitor for adverse effects, increased bp
headache, hematoma formation, hemorrhage, shortness of breath, chills, fever
117
Episodic, reversible oxygen insufficiency is called
angina
118
The main purpose of using antianginal drugs is to
dilate coronary arteries
119
Beta blockers prevent the development of
myocardial ischemia and pain
120
Nitroglycerine is admin. to decrease the heart’s ? and ? to the heart muscle
workload and increase blood supply
121
Class ? antidysrhythmic drugs may be the least toxic. Also know as ?.
2 and beta blockers
122
Which drug is a common beta blocker used as an antidysrhythmic?
propranolol
123
Which Ca channel blocker acts principally on the AV node and slows conduction?
veramapril
124
The best description of how antihypertensives work is that they: ? vessels to ? pressure.
vasodialate and reduce
125
Which blood element has a protective property for heart disease?
HDL
126
Antihyperlipidemia drugs work to ? cholesterol and triglycerides.
lower
127
When administering spironolactone, the nurse monitors the client for ? (electrolyte imbalance).
hyperkalemia
128
Clients on blood thinning medication should be monitored for internal bleeding, which may be indicated by what:
sudden decrease in bp
multiple red spots on skin
black tarry stools
129
Common adverse effects of antidysthrythmic drugs include what:
dysrhythmias
lightheadedness
hypotension
weakness
130
Prevents angina
nitroglycerin
131
Has common a/e of hypotension
beta blockers
132
Lower blood pressure
Ca channel blockers
133
Have common a/e of headache
nitroglycerin and Ca channel blockers
134
Cause vasodilation
Ca channel blockers
135
Decrease HR
Ca channel blockers and beta blockers
136
Treats angina
nitroglycerin
Ca Channel blocker
propranolol
137
Prevents cell aggregation
antiplatelet
138
Dissolves existing thrombi
thrombolytic
139
Prevents formation of new thrombi
anticoagulant
140
What is a dysrhythmia
any deviation from the normal rhythm of the heart
141
What do antidysrhythmics do
use to treat and prevent disturbances in cardiac rhythm
142
What is the Vaughn Williams Classification
system used to classify antidysrhythmic drugs
143
What is in the mechanism of action in Class I antidysrhythmics
Membrane-stabilizing drugs
Fast sodium channel blockers
Divided into Ia, Ib, and Ic drugs, according to effects
144
What is the class 1a classification of antidysrhythmic drugs
Ex: of a drug quinidine
-Block sodium (fast) channels
-Delay repolarization
-Increase the action potential duration (APD)
-Are used for atrial fibrillation, premature atrial
contractions, premature ventricular
contractions, ventricular tachycardia, Wolff–
Parkinson–White syndrome
145
What is the class 1b classification of antidysrhythmic drugs
Ex of a drug phenytoin (Dilantin), lidocaine (Xylocaine)
-Block sodium channels
-Accelerate repolarization
-Increase or decrease the APD
-Are used for ventricular dysrhythmias only
Premature ventricular contractions,
ventricular tachycardia, ventricular fibrillation
146
What is the class 1c classification of antidysrhythmic drugs
Ex of a drugpropafenone (Rythmol)
-Block sodium channels (more pronounced
effect)
-Have little effect on APD or repolarization
-Are used for severe ventricular dysrhythmias
-May be used in atrial fibrillation/flutter,
147
What is in the mechanism of action in Class II antidysrhythmics
b-blockers: acebutolol, propranolol (Inderal)
- Reduce or block sympathetic nervous system stimulation, thus reducing transmission of impulses in the heart’s conduction system
- Act as general myocardial depressants for both supraventricular and ventricular dysrhythmias
- Are also used as antianginal and antihypertensive drugs
148
What is in the mechanism of action in Class III antidysrhythmics
Ex of a drug amiodarone
- Increase APD
- Prolong repolarization in phase 3
- Used for dysrhythmias that are difficult to treat
149
What is in the mechanism of action in Class IV antidysrhythmics
Ex of a drug verapamil
Calcium channel blockers
Inhibit slow-channel (calcium-dependent)
pathways
Depress phase 4 depolarization
Reduce AV node conduction
Are used for tachycardia; rate control for
atrial fibrillation and flutter
150
There are two unclassified antidysrhythmics, what are they
digoxin and adenosine
151
What does adenosine do
-Slows conduction through the AV node
-Is used to convert paroxysmal supraventricular
tachycardia to sinus rhythm
-Has a very short half-life—less than 10 seconds
-Is administered only as fast intravenous (IV)
push
152
What can all antidysrhythmics do
cause dysrhythmias
153
What are some adverse effects for antidysrhythmics
Hypersensitivity reactions
Nausea
Vomiting
Dizziness
154
What should the nurse be assessing when giving antidysrhythmics
-thorough medical history
-baseline for bp, pulse, I & O and cardiac
rhythm
-labs indicating potassium level before
initiating therapy
Assess for contraindications
Assess for potential drug interactions
During therapy, monitor cardiac rhythm, heart rate, blood pressure, general well-being, skin colour, temperature, heart and lung sounds
Assess plasma drug levels as indicated
Monitor for toxic effects
```
Monitor for therapeutic response
Decreased BP in hypertensive patients
Decreased edema
Decreased fatigue
Regular pulse rate
```
Monitor for adverse effects
155
What are some teaching points for antidysrhythmias
Instruct patients to take medications as scheduled and not to skip doses or double up for missed doses
Instruct patients regarding dosing schedules and adverse effects to report to physician
Instruct patients not to crush or chew any oral sustained-release preparations
```
Ensure that the patient knows to notify health care provider of any worsening of dysrhythmia or toxic effects
Shortness of breath
Edema
Dizziness
Syncope
```
Patients taking b-blockers, digoxin, and other drugs should be taught how to take their own radial pulse for 1 full minute, and told to notify their physician if the pulse is less than 60 beats/min before taking the next dose of medication
