Week 11: Cardiovascular Part 2 Flashcards
Vasodilators
drugs that reduce BP by acting directly on vascular smooth muscle and thereby decrease peripheral resistance
can act as anti-hypertensives
2 Kinds of Vasodilators
- Selective to arterioles (only dilate arterioles - ex: Hydralazine) - Direct Vasodilator
- Affect both arterioles and veins (Huge effect on the body - ex Nitroprusside - will oftne need to be titrated)
Selective to arteriole vasodilators will decrease ____
afterload
Vasodilators affecting arterioles and veins decrease ___ and ___
afterload and preload
The fastest acting antihypertensive type is…
vasodilators that affect the arterioles and the veins
How can vasodilators precipitate angina, MI, or CHF?
SNS will activate by reflex action which can lead to increased HR, CO, and force of contraction
This means generally there needs to be a combined therapy with something like a beta blocker
What is the prototype direct vasodilator, antihypertensive drug
hydralazine (Apresoline)
Action of hydralazine
thought to have direct action on blood vessels, to cause arteriolar vasodilation and increase renal blood flow (helps the kidneys)
What is the bonus effect of a vasodilator like hydralazine
it also increases renal blood flow which is beneficial for the kidneys
What is the most common route for hydralazine and why is it this important to know?
Oral - because it has an extensive first pass
ADRs of hydralazine
HYPOTENSION
(Reflex) PALPITATIONS/TACHYCARDIA
Other: HA, Anxiety, Mild Depression, Dry mouth, Unpleasant taste in mouth, NV
What kind of vasodilator is hydralazine
direct acting vasodilator
so it is selective to arterioles
Why is there frequent monitoring in the early stages of hydralazine therapy?
Because of differences in metabolism, some people metabolize this quicker while others do not so we need to be monitoring the BP response to watch for the effect
Calcium Channel Blockers
Type of drug that causes arteriolar dilation, blocks the renin system, AND DECREASES MYOCONTRACTILITY
It inhibits the movement of Ca ions across cell membranes to decrease mechanical contraction of the heart
“Calcium Antagonists”
Does perform some coronary vessel and peripheral artery dilation but focuses on cardiac muscle membranes
Calcium Channel Blocker results and treatment is similar to what other type of drug for antihypertension
Beta Blockers (but this works on calcium instead)
Calcium antagonist (Ca Channel Blocker), Antianginal, and Antiarrhythmic (and by result Antihypertensive) Prototype Drug
verapamil (Calan, Isoptin)
Action of verapamil
produces blockage of calcium channels in blood vessels and in the heart (Dual Effect)
This leads to a multitude of effects where the HR slows and does not beat as strong - similar in some ways to beta blockers
What are the 6 important effects of verapamil’s action
- Arteriolar Dilation and resultant lowering of BP
- Increase in coronary perfusion
- Slows SA node causing reduction in heart rate
- Decrease in nodal; conduction in AV node
- Decrease in force of myocardial contraction
- inhibition of renin release
Route of verapamil
oral - but there is an extensive 80-90% first pass so there is an IV form for emergencies
ADRs of verapamil
BRADYCARDIA
HYPOTENSION
SEVERE TACHYCARDIA (Some Reflex)
CONSTIPATION (HIGHER THAN IN OTHER DRUGS)
Other: Nausea, Discomfort, Dizziness, HA, Flushing, Pruritis
When is verapamil contraindicated
In an AV block and conditions of reduced myocardial contractility, severe hypotension, and severe CHF
- avoid conduction problems, reduced contractility, further drops in BP and worsens heart failure
What could increase calcium channel blocker levels (like verapamil) if taken with the drug
Grapefruit Juice (So dont drink it)
Renin-Angiotensin System Antagonists
Newer class of drugs - 1980s
Inhibits the action of renin-angiotensin-aldosterone system
Includes ACE Inhibitors and ARBs
can act as antihypertensives
Angiotensin II is a potent ____
vasoconstrictor (so if we block it we can open vessels and decrease BP)
ACE Inhibitors
Prevent the conversion of angiotensin I to angiotensin II
Inhibits the ACE enzyme, not the angiotensin 2 directly
All ACE Inhibitors end in ____
-pril
ARBs
Angiotensin Receptor Blockers
Block binding of angiotensin II to receptors
All ARBs end in ____
-sartan
Angiotensin II (ACE) Inhibitor Prototype Drug
lisinopril (Prinivil, Zestril)
Action of lisinopril
Inhibits ACE to prevent angiotensin I –> Angiotensin II conversion
What is the result of lisinopril inhibiting ACE
- reduced vascular tone and a direct lowering of BP
- Decreased aldosterone release and less Na Retention –> Less Na retention means less water retention meaning a DIURETIC EFFECT and decreases BP
Route of lisinopril
mostly Oral
ADRs of lisinopril
- ACE INHIBITOR COUGH - Dry nonproductive cough, chronic - 5-30% get this
- HYPOTENSION
- POSSIBLE HYPERKALEMIA
Other: Pruritis, Rashes, Dizziness, HA
Rare: Neutropenia, agranulocytosis, hepatotoxicity
Why is there a risk for hyperkalemia with lisinopril
because there is less Na retention leading to increased K retention
What could be concerning for a renal impaired patient taking lisinopril
the retention of K they cannot rid of
We would never give anyone on an ACE inhibitor what kind of drug alongside it
any drug that increases Potassium
What is the Black Box Warning for All Ace Inhibitors like Lisinopril
Fatal Injury and death when taking during pregnancy - mainstay of therapy for heart failure
What are the 2 effects ACE Inhibitors can do that is helpful
- Anti-hypertensive
- Treatment of heart failure
Why can ACE inhibitors be used for heart failure treatment
because it blocks aldosterone and also low sodium retention decreases fluids thus decreasing strain
Angiotensin II Receptor Antagonist (ARB), Antihypertensive Prototype Drug
losartan (Cozaar)
What ADR seen in ACE inhibitors is not seen with ARBs
the cough
Action of losartan
Blocks binding of Angiotensin II to type I receptors in blood vessels and other tissues
Inhibits RAA system better and more selectively than ACE inhibitors
Route of losartan
oral
ADRs of losartan
HYPOTENSION
DIZZINESS
Other: Insomnia, GI, Muscle Pain and Cramps, Occasionally increased liver enzymes
NOT AND ADR = COUGH
Black Box Warning for ARBs like losartan
Do not use in pregnancy because of effects in the RAA system
Same as ACE inhibitor’s black box warning
Maximum effect for losartan is seen when?
within 3-6 weeks
Why is losartan sometimes given with a diuretic like HCTZ in the form of the combo drug Hyzaar
for a boosted anti hypertensive effects
Things that ACE Inhibitors Do
Vasodilation
Decreased blood volume (less sodium retention)
Decreased cardiac and vascular remodeling
Potassium retention
Fetal injury
What is it about ACE Inhibitors that leads to the unique cough
ACE inhibitors also prevent the breakdown of BRADYKININ (which is a vasodilator and inflammatory mediator) –> This leads to Vasodilation, Rare Angioedema, and the COUGH
Angina Pectoris
a symptom of transient myocardial ischemia perceived as chest pain or discomfort.
Generally precipitated by a condition that increases myocardial oxygen demand or decreases oxygen supply (primarily in diseased vessels – but can be in normal ones if constricted).
3 Classes of Drugs for Angina Pectoris Treatment
Nitrates
Beta Blockers
Calcium Channel Blockers
How do nitrates help treat angina
reduce O2 demand by reducing preload and afterload
How do beta blockers help treat angina
decrease O2 consumption by decreasing heart rate, BP, and myocardial contractility
Blocking Beta 1 causes decreased HR and contractility, also decrease reflex tachycardia caused by other drugs
How do calcium channel blockers help treat angina
produce coronary and systemic arterial vasodilation, reduce afterload, HR, and contractility
Have many actions beside anti anginal effects but reduces myocardial O2 consumption
Anti Anginal Prototype Drug
Nitroglycerin
Action of Nitroglycerin
Relaxes vascular smooth muscle and both arterial and venous vessels BUT works mainly on the venous system in those with CAD - exact mechanism is unknown but peripheral resistance decreases and venous return to the heart is decreases!
Dilating veins decreases preload and BP
Net result: decreased myocardial O2 consumption and angina relief
What is the issue with Nitroglycerin and CAD
those with CAD are physically unable to have their vessels dilate with nitroglycerin since they are hardened
Why can nitroglycerin still be helpful despite someone having CAD
It cannot dilate the coronary arteries, but it will dilate everything else - like the venous system - so blood can stay in extremities instead of going back into the heart which will decrease preload and work load overall since there is less circulation going to the heart –> results in cardiac demand decreasing
So basically, it opens everything else up beside the coronary vessels
What is the preferred route of absorption for nitroglycerin?
Sub-lingual (under tongue and absorbed quickly) very well
Can also be given IV oral and skin
ADRs of Nitroglycerin
HA (Dilated vessels in the head causing a pounding HA)
!!REFLEX TACHYCARDIA
!!HYPOTENSION (all the smooth muscles are relaxing)
Other: Dizziness, Syncope, Flushing of skin
Why does BP need to be checked 5 minutes after giving Nitroglycerin
drops BP and this can happen fast
What needs to be done when giving nitroglycerin
you have to wear gloves because it can absorb through the palms and give a pounding headache for the nurse as well
What is unique about nitroglycerin dosage
it is INDIVIDUALIZED
Used to be take 3 tablets then call 911 - but now you take one tablet and if it doesnt help call 911 (dont drive and dont have someone else drive you)
When is nitroglycerin use contraindicated
When another drug that causes blood vessel dilation - such as sildenafil (Viagra) - is taken because it can cause life threatening hypotension and cardiac collapse
Nitrate Tolerance
Tolerance occurring for nitroglycerin in its topical patch and ointment form
Creating a nitrate free period of 10-12 hours without the patch while they sleep can prevent this
What is important to know about the container nitroglycerin comes in
it comes in a brown bottle to protect it from sunlight and moisture so the patient should not eb putting it into pill sorters
Usual Causes of Congestive Heart Failure
MI
HTN
CAD
Arrhythmias (especially AF)
Goals of Congestive Heart Failure Medication Therapy
decrease cardiac workload
improve cardiac performance
3 Classes of Drugs For Congestive Heart Failure Therapy
- Diuretics
- Vasodilators (Nitrates, Hydralazine and others, ACE inhibitor)
- Inotropic Agents
digoxin (Lanoxin) increases ____
contraction (increased contractility, improve efficiency, decreased HR, better filling)
It is important to monitor for ___ depletion with diuretics
potassium
Diuretics
Class of drugs reducing body fluid volume (Helps with HTN, heart failure, cirrhosis, renal disease, increased ICP and increased Intraocular pressure)
Less volume = you have the less work for a failing heart
Many Diuretics work to do what
decrease reabsorption of sodium and water along the renal tubule - leaves Na in the filtrate to increase loss of fluid instead of having it go back into the bloodstream
Degree of diuresis depends on…
which part of the tubule is affected - so depending on what area it acts on (areas where it acts on sodium or not) will determine fluid loss and effectiveness
Common ADR of Diuretics
Electrolyte loss other than sodium!
Particularly POTASISUM - serious one to worry about
Thiazide Diuretic
Family of diuretic acting on the distal tubule to increase Na, Cl, K, and H2O excretion
ex: HCTZ
ADRs - lyte and fluid losses
All thiazide diuretics end in what
-thiazide
Thiazide Diuretic Prototype Drug
HCTZ / Hydrochlorothiazide (Hydrodiuril)
Action of Hydrochlorothiazide
Inhibition of sodium reabsorption at cortical diluting segment of the nephron, including portions of ascending loop of henle and distal convoluted tubule
exact mechanism unclear
promotes excretion of Na, Cl, and H2O and K is also lost (Washes out many Lytes)
ADRs of Hydrochlorothiazide
HYPOKALEMIA and other lyte disturbances
Other: Gastric irritation, anorexia, cramping, constipation, juandice, HA, vertigo, paresthesias, Allergic manifestation
What type of allergies contraindicated hydrochlorothiazide use
sulfur allergies - it is a sulfonamide derivative
Thiazide diuretics are only considered mild/moderate diuretics, therefore it is not…
used for intense fluid loss or emergency situations
Loop Diuretic Prototype Drug
furosemide (Lasix)
Loop Diuretics
Works on the loop of henle to promote excretion of sodium, chloride, potassium and water
Causes a very strong diuretic effect
ADRs r/t fluid and lyte losses - especially K
If there is an acute or dangerous fluid overload or pulmonary edema what kind of diuretic is often given
loop diuretic (strong fluid loss)
Action of furosemide
Inhibits active Cl transport in thick portions of the ascending limb of the loop of Henle
Passive sodium transport inhibition occurs
By blocking the ascending portion of the loop of henle, where a lot of Na is reabsorbed, a lot of diuresis occurs
Why is furosemide called Lasix
it lasts six hours
What is important to know about the distribution of furosemide
Orally - onset in 30 minute, peaks in 1-2 hours, duration of 6-8 hours
IV - onset in 5 minutes, peaks in 30 , duration 2 hours
ADRs of furosemide
NVD (From lyte imbalances) - dont lie them down after this
POSTURAL HYPOTENSION
HYPOKALEMIA
Other: Dermatitis, Pruritis, Blurring of vision, ototoxicity, allergies
What allergy contraindicates furosemide use
sulfur allergy (sulfonamide derivative)
In what situations is furosemide contraindicated in?
Contraindicated in pregnancy and nursing mothers
States of anuria ( wont make kidneys work and causes more damage)
Hepatic coma (can take too long to rid of toxins)
Electrolyte depletion (already K depleted)
Since loop diuretics are more potent than thiazide diuretics they are not ideal for treating ___ but are ideal for ___
HTN; CHF
What is an important long term thing to consider when taking furosemide
it promotes calcium excretion so consider long term bone health
Osmotic Diuretic
A type of diuretic where a sugar like Mannitol will pull water, like plasma proteins do, from vascular spaces through osmosis and the water and sugar will filter into urine and allow for large diuresis
Osmotic Diuresis Prototype Drug
Mannitol
Action of Mannitol
Mannitol pulls water from vascular spaces (Osmosis) and pulls it to the kidneys during excretion - large enough where it wont cross places
Non-electrolytes are filtered by glomerulus, but not significantly reabsorbed or metabolized(stays its own way in and out) The high osmolality also decreases reabsorption of water.
Whats important to know about the distribution and excretion of Mannitol
Distribution - stays in vascular compartment - does not cross membranes
Excretion: Renal, unchanged
ADRs of Mannitol
Depends on amount of drug used and its effect on fluid balance
SE: HA, nausea, chills, mild chest pain, lyte imbalances
EXACERBATION OF HEART FAILURE IF A LOT OF FLUID IS DRAGGED TO THE HEART TO PUMP
When is Mannitol mostly used
Emergent cerebral edema - pulls fluid from brain tissue
not really a cardiac diuretic more of a cerebral effect
Contraindications for Mannitol
Severe CHF
HTN (lots of fluid in bloodstream)
Chronic Edema (Empties blood stream with edema still in third space - works too fast)
Why are filter needles always used with mannitol
because it can crystallize
A big way to treat heart failure is for drugs to improve ____
constractility
Cardiac Glycosides
group of drugs including digoxin
Strengthens force of myocardial contraction, slows conduction, and slows HR
net effect: increasing CO, and controlling rhythm and rate
Cardiac Glycoside Prototype Drug
digoxin (Lanoxin)
Action of Digoxin (Lanoxin)
Alters sodium and potassium transport, also leading to alteration in calcium movement
Indirect actions: intensifies vagus nerve effects - further slows the heart, AND a diuretic effect on the kidney
Some steroidal element similar to sex hormones
Effects of the Action of Digoxin
- Inotropic Action
- Chronotropic Action
- Dromotropic Action
Inotropic
strength on contraction
digoxin increases this
Chronotropic
heart rate
digoxin decreases this
Dromotropic
conduction velocity
digoxin slows this
Digoxin is esp useful in what patient situations
HF
A Fib and Flutter (drop in CO)
Digoxin effects ___ more than ___ to make the heart more efficient
rate more than rhythm (but does affect both)
Route of Digoxin
oral - variable depending on dissolution
Therapeutic Digoxin Blood Levels
0.5-2.0 ng/mL
ADRs of Digoxin
ANOREXIA, NVD, HEADACHE - Might indicate Toxicity
VISUAL DISTURBANCES
GYNECOMASTIA
Other: Weakness, Restlessness, Nervous irritability, Cardiotoxicity, GI, CNS
Almost every type of dysrhythmia can be produced by…
digoxin toxicity
What is the visual disturbances from digoxin like
funny yellow green halows and rings around lights
What are the 3 Side Effects may indicate Digoxin Toxicity
Headache
Anorexia
NVD
Digitalizing
getting digoxin levels up quickly with a higher dose
it is than maintained with a maintenance dose that is lower
Antidote for Digoxin Toxicity
Digoxin Immune FAB
What vitals are important to check prior to giving digoxin
APICAL PULSE RATE and RHYTHM (BP less important here)
Why is giving diuretics with digoxin a potential problem
Diuretics lead to K loss which can lead to digoxin toxicity
So we need perfect or higher K levels or we have an issue
Why is giving antacids with digoxin an issue
because antacids interfere with absorption of digoxin
____ increases the effects of digoxin even to the point of toxicity
Hypokalemia
So we need to monitor lyte levels, especially potassium
Cardiac Electrolyte Prototype Drug
Potassium
Potassium
Major positively charged ion in intracellular fluid
can be used for prophylaxis with a diuretic and/or digoxin therapy
should never be IV pushed/bolus
Action of Potassium
Major positively charged ion that plays an important part in the following:
- Muscle Contraction
- Conduction of nerve impulses
- Enzyme action
- Cell membrane function
Most common reason for giving potassium is what
as prophylaxis from Digoxin or Diuretics
Absorption route of potassium
Oral, very good
can also give IV somtimes
ADRs of Potassium
HYPERKALEMIA - with all of its effects especially on cardiac electrical activity
Other: May cause GI Pain, distention, abdominal cramps, diarrhea, weakness, and paralysis
What route of potassium is for prophylactic diuretic therapy
oral
What is important to think about regarding the administration of oral potassium
It should be given with a full glass of water
It has an unpleasant taste if liquid or elixir and it may smell like orange soda but the taste is highly unpleasant
Dysrhythmias arise from what 2 general causes?
- Disturbance in automaticity
- Disturbance in conduction
What sort of drugs are used for their antiarrhythmic effects other than Antiarrhythmic agents specifically?
beta blockers, calcium channel blockers, digoxin
What causes arrhythmias
Changes in ion currents through the channels of the myocardial cell membrane are the main cause of cardiac rhythm changes and arrhythmias (Abnormal rhythms)
Any drug used to treat an arrhythmia can also cause arrhythmias! – ex could fix rhythm but then make one too slow for example!!!!!!!!
Anti-arrhythmic Class 1A prototype drug
Quinidine - Class 1 A
Action of Quinidine
direct action on cardiac cell membrane
Stabilizes cell membrane by preventing ready movement on Na and K across cellular barrier
Decreases impulse generation, prolongs refractory period of atria and ventricular fibers and decreases conduction
Used for atrial arrhytmias/dysrhythmias
Route of Quinidine
Oral, good (form intestine - alkaline pH)
ADRs of Quinidine
NVD - too much can lead to loose stools and quinidine toxicity
CV - effects vary to complete heart block and ventricular disorders including Ventricular Fibrillation
Other: tinnitus, vertigo, visual disturbances, thrombocytopenic purpura, rashes, urticaria, hypotension
Most common quinidine ADR is…
GI Disturbance (NVD)
Most serious quinidine ADR is…
cardiac rhythm changes
Quinidine is mostly used with what kind of dysrhythmias?
Atrial Dysrhythmias - not used too often anymore though
It still has some activity in the ventricles as well though
Antiarrhythmic Class 1B Prototype Drug
Lidocaine (Xylocaine)
Lidocaine is both a _____ and ____ ___
anti-arrhythmic and local anesthetic
Lidocaine is mostly used with what kind of dysrhytmias?
Ventricular Arrhythmias (extra ventricular beats like PVCs)
Why is a continuous IV infusion of lidocaine needed
because it has a very short half life
Most common ADRs of lidocaine are…
ones affecting the heart and CNS
Action of lidocaine (as an antiarrhythmic)
Similar electrophysiologic properties as quinidine - anesthetizes the cell membrane to stop unusually sources impulses
Depresses excessive automaticity of ectopic pacemakers (esp. in HIs-Purkinje fibers)
LITTLE EFFECT ON ATRIA
What route is lidocaine given
IV usually (continuous) because there is a huge first pass effect and irritation orally
How fast is lidocaine distributed
Rapidly - onset is in 10-90 seconds, duration of 20 minutes, and half life of 2 hours
ADRs of Lidocaine
CNS DISTURBANCES: agitation, disorientation, muscle twitching
CV: heart block, hypotension, resp or cardiac arrest occurrence, bradycardia
Other: Drowsiness, Blurred vision, nausea, tinnitus, euphoria, resp depression, mental status changes
Lidocaine as an anti-arrhythmic is only given on what units
critical care units
The drug of choice in treating ventricular dysrhythmias is…
lidocaine - it gets in quick and works quick
Caution using lidocaine with what kinds of patients
Liver Disease (hepatic blood flow affects rate of drug clearance) - so it wont clear well and bad ADRs occur
Your patient is taking atorvastatin (Lipitor). Patient teaching should include contacting the provider IMMEDIATELY for…
a. Diarrhea
b. Intermittent headaches
c. Nausea
d. Severe muscle pain
D. Severe muscle pain
lots of muscle effects in the ADRs
Which symptoms may indicate hyperkalemia?
A. Anorexia, NVD, constipation
B. Irregular pulse, muscle weakness, constipation
C. NVD, weak pulse, cardiac arrhythmias
D. Elevated LDH, muscle cramps
Answer: C. nausea, diarrhea, weak pulse, cardiac arrhythmias
Hyperkalemia revs up the GI tract - constipation is more hypokalemia
Your patient is prescribed IV furosemide (Lasix). You should administer this medication how fast?
over 1-2 minutes
Which of the following adverse reactions is associated with ACE inhibitors
a. Bradycardia
b. Cough
c. HTN
d. Ankle edema
B. Cough
CHF Management includes all of the following except:
A. Diuretics
B. Positive Inotropic Agents
C. ACE Inhibitors
D. Anti-arrhythmic agents
D. Anti-Arrhythmic Agents
For general heart failure it is not associated with arrhythmic agents out of these choices
Prototype Potassium Sparing Diuretic
Spironolactone (Aldactone)
Action of Spironolactone
Antagonizes aldosterone by binding to the protein that permits K secretion at the distal tubule
Works in the distal tubule to promote sodium and water excretion BUT also reabsorption of potassium!
Weakest Diuretic Type
potassium sparing - a slow and mild diuresis
Route of spironolactone
oral
ADRs of Spironolactone
- HYPERKALEMIA
- Male Gynecomastia or Female Breast Soreness/Menstrual Irregularities - Steroid Effect
Other: Anorexia, NVD, HA, drowsiness, Ataxia, mental confusion
NO HYPOTENSION SINCE ITS SLOW AND MILD
What is common to see alongside spironolactone
another diuretic for a synergistic effect while retaining K
