Cardiovascular Meds Flashcards
List drug strategies to improve cardiac function
- Directly increase cardiac contractility
- Reduce workload of the heart by:
- reducing contractility → direct effect
- reducing afterload → indirect effect
- reducing preload → indiriect
- Increase myocardial blood flow
- Manage hemostasis
- Other
- antiarrhythmic drugs
- statins
what are ionotropic agents?
used to increase force of contraction
T/F: intravenous positive iontrophic agents can be used anywhere
FALSE
should only be used in inpatient settings
and then only in pts manifesting S/S of low CO-syndrome
T/F: pt services are probably on hold with pts recieving IV ionotropic therapy
TRUE
List several ionotrophic agents
- Dopamine
- Dobutamine
- Milrinone
what is the effect of low-dose dopamine?
associated with dilation within renal and splanchnic vasculature resulting in enhanced diuresis
what is the effect of moderate-dose dopamine?
enhances cardiac contractility and HR
what is the effect of high-dose dopamine?
increased afterload through peripheral vasoconstriction
describe dobutamine
- +ionotrophic and chronotrophic agent
- (increased contracility and HR)
- decreases afterlod
- beta-receptor agonist
- improved end organ perfusion
- improves MAP
describe Milrinone
- type 3 phosphodiesterase inhibitor
- increases iontrophy, chronotrophy, and lusitrophy
- contractility, HR, rate of myocardial relaxation
- increases intramyocardial ATP
- potent vasodilator
- used in management of pulmonary HTN
what is Digitalis used to treat and how does it work?
- Used to treat impaired cardiac contractility typically caused by HF
- works by directly increasing cardiac contracility
- direct ionotrophic effects
what else is digitalis referred to as?
- Foxglove
- cardiac glycoside
- digoxin
- digitoxin
how does Digitalis increase cardiac contracility?
- increases Ca2+ influx into myocytes
what are the electrophysiological effects of digitalis?
- increases the AV node’s refractory period, decreasing the ventricular response (anti-arrhythmic)
- used to treat A-Fib, Atrial tachycardia and HF
- can cause reflex stimulation of the vagus nerve
- decrease HR and contractility
List drug classes that work to directly reduce contractility and thus reduce workload of the heart
- Beta-blockers
- Ca2+ channel blockers
what is the effect on the heart when a beta-1 agonist is given?
increased HR
increased contractility
what is the clinical use of beta-1 agonists? What is the impact on cardiac work?
- Clinical use
- treat conditions of severe cardiac decompensation
- cardiovascular shock
- in conjunction with cardiac surgery
- HF
- treat conditions of severe cardiac decompensation
- Impact on cardiac work
- increases work load of the heart
what is the effect on the heart when a beta-1 antagonist is given?
decreased HR
decreased contractility
limit impact on sympathetic NS on the heart
what is the clinical use of a beta-1 antagonist and what is the effect on cardiac work?
- Clinical use
- used to treat compromised or diseased hearts
- Impact on cardiac work
- reduces workload of the heart
- reduces functional capacity
T/F: Beta-1 antagonists affect primarily the heart
TRUE
(called beta-blockers)
what is the effect of beta-blockers on the heart?
negative chronotropic and ionotrophic effect
(reduces workload of the heart)
differentiate between the 2 subtypes of beta-blockers
- non-specific beta-blocker
- positive effect on the heart
- negative effect (smooth muscle contraction) on bronchial smooth muscle
- cardioselective beta-blocker
- specific for B-1 receptors which are found most frequently on cardiac tissue
Beta-blockers suffic
-olol
Adverse effects of beta-blockers
- receptor overreach
- can cause bronchoconstriction which is not a problem in most ppl but becomes a problem in those with pulmonary disease (cor pulmonale)
- can cause excessive depression of cardiac function
- OH
- depression, lethargy and sleep disorders (long term use)
- reduced peak HR
- reduced exercise capacity
7.
how to calculate HRmax for someone on a beta-blocker
HRmax = 164 - 0.7*age
what is the effect of Ca channel blockers on the heart?
- reduce calcium entrance into myoctyes causing:
- reduced contractility
- reduced energy demands on heart
- reduced CO
AE of Ca channel blockers
- decreased BP
- flushing
- bradycardia
- HA
- dizziness
- peripheral edema
- May increase risk of MI
*result in peripheral vasodilation which explains many AE
List drugs that reduce afterload
- Alpha blockers
- direct vasodilators
- beta-blockers
- centrally acting agents
what is the effect of alpha blockers?
smooth muscle relaxation, vasodilation and decreased TPR
what is TPR?
Total Peripheral Resistance (aka systemic vascular resistance or SVA)
- the resistance to blood flow offered by all of the systemic vasculature beds to blood flow
- largely determined by changes in blood vessel diameter
*
AE of alpha blockers
- these are systemic drugs with systemic effects
- reflex tachycardia secondary to hypotension
- OH
- edema of LE
- syncope
- SOB
- Weakness
- N/V
how do direct vasodilators work?
work directly on smooth muscle cells to cause relaxation and thus reduce afterload and the workload on the heart
how can beta-blockers reduce afterload?
reduce vascular smooth muscle contraction and SVR
how do centrally acting agents act to reduce afterload?
- appear to inhibit sympathetic outflow from the brainstem
- decrease HR
- decrease contractility
- decrease TPR
- act like alpha 2 antagonists
- often given with a diuretic
AE of centrally acting agents
- dry mouth
- dizziness
- drowsiness
- hypotension
how does influencing preload reduce the workload of the heart?
changes in blood volume affect arterial pressure by changing CO
they influence the Frank-Sterling law to reduce LVEDV and thus reduce cardiac contracility
list drug classes that work to reduce preload
(and thus reduce the workload of the heart)
- Diuretics
- loop diuretics
- thiazide diuretics
- potassium sparing diuretics
- ACE inhibitors
- ARBs
- Aldosterone antagonists
how do diuretics reduce preload?
they increase the amount of urine formed
- increases diuresis which decreases blood volume
- act directly on the kidneys to increase water and sodium excretion
how do loop diuretics work?
- act on the ascending limb of the loop of Henle
- inhibit the reabsorption of Na+ and Cl-
- loss of K+
how do thiazide diuretics work?
- act on the distal convoluted tubules to inhibit Na+ reabsorption
how do K+ sparing diuretics work?
- interfere with sodium-potassium exchange mechanism in distal convoluted tubules
- are less effective at producing diuresis but are K+ sparing
rank the diuretic classes based on AEs
loop > thiazides > potassium sparing
loop diuretics are used more for _______
diuresis than HTN control
Diuretics AEs
- geriatric pts → more susceptible to resulting hypotension
- dehydration
- OH
- increased TPR
- activate renin-angiotensin system
- Electrolyte imbalance
- hyponatremia → AMS
- hypernatremia → cardiac dysrhythmias
- OH and falls precaution
- Can cause urinary incontience secondary to increased urine production
why do pts on diuretics call them “water pills?
they will frequently require bathroom breaks and
S/S of toxicity from diuretics
- anorexia
- N/V
- confusion
- increased weakness
- paresthesia
List all the effects angiotension II has
- constricts walls of arterioles
- stimulates Na+ reabsorption in the kidneys
- stimulates aldosterone release from adrenal cortex which causes kidneys to reclaim still more sodium and water
- stimulates catecholamine release
- net effects
- vasoconstriction
- fluid retention
- increased afterload
what is the entire goal of the renin-angiotensin system?
preserve water and electrolytes
what are the net effect of ACE Inhibition?
- decreased vascular smooth muscle tone
- inhibition of aldosterone secretion
- decreased renin activity/production
AE of ACE inhibitors
typically well tolerated
- allergic reaction (some may have this and it presents like a cough)
- GI discomfort
- Dizziness
- Chest pain
- Persistent cough
- Weakness
suffix for ARBs
(ARBS = angiotensin II receptor antagonists)
suffix = -artan
what is aldosterone?
a steroid hormone produced by adrenal cortex
- plays a central role in regulating BP
- acts at the level of the distal convoluted tubule and collecting ducts
- increases reabsorption of ions (Na+) and water in the kidney
- conserves Na+, secretes K+, increases water retention, increases BP
list classes of drugs available to treat HTN
- Direct vasodilators
- Beta-adrenergic blockers
- Centrally acting agents
- Alpha blockers
- Ca+ channel blockers
- ACE Inhibitors
- Angiotensin II receptor antagonists (ARBs)
- Diuretics
- Aldosterone receptor blockers
list drug classes that work to increase blood flow to the myocardium
(thus increasing myocardial blood flow)
- Nitrates
- organic nitrates
- nitroglycerin patches
how do nitrates work on the myocardium?
- venodilator → decrease venous return and decrease preload
- arteriodilator → decrease afterload
- acts as a relaxant for coronary artery smooth muscle and systemic arterial smooth muscle
T/F: organic nitrates like nitroglycerin act specifcally on coronary arteries
FALSE
they produce a general vadodilation not specifically a coronary artery dilation
how can nitroglycerin be delivered?
- Oral → first pass effect is substantial
- Sublingual → best method to treat acutely/avoids 1st pass effect
- Buccal → cheek and gum
- Transdermal patches → prophylactic
things to remember with nitroglycerin patches
- not effective acutely/immediately
- must be changed every 24 hrs
- change where patch is applied to avoid skin rash
- always use it even if you are feeling well
- don’t suddenly stop using it
- don’t double up if patch is forgotten
- dispose of used
when should a pt contact an MD when they are on a nitroglycerin patch?
if they develop blurred vision, dry mouth, skin rash, dizziness, or fainting
List drugs that manage hemostasis
- Thrombolytic agents
- Antiplatelet agents
- Anticoagulants
what is hemostasis?
- Intrinsic process which causes bleeding to be stopped
- requires the combined activity of vascular, platelet and plasma factors
- vessel wall injury trigger attachment and activation of platelets and causes vasoconstriction
- platelets become “sticky” and attach to the area of vessel wall injury
- plasma factors interact to convert fibrinogen to fibrin which helps form clot
how do thrombolytics work?
act by degrading a formed clot
AE of thrombolytics
- hemorrhage
- be alert for signs of heavy bleeding
- severe HA
- joint or back pain
- no antidote
- GI distress
- unusal bleeding
unusal bleeding sites that may occur when a pt is on thrombolytics
- nose bleeds
- blood in urine or stool
- bruising
- unusually heavy menstrual flow
- back pain or joint pain may indicate abdominal or joint hemorrhage respectively
what are anticoagulants?
chemical substances that help prevent or slow the coagulation of blood (formation of clots)
- these are preventative
- commonly called blood thinners
- act by interfering with the proteins in the blood that are involved in the coagulation process
list some drugs that are anticoagulants
- Heparin
- Coumadin (Dicoumarol, Warfarin)
- Xarelto
- Eliquis
- Lovenox
Anticoagulants are used primarily to treat _____
- strokes
- MIs
- DVT
- PE
- Hx of blood clots, post surgery, inactivity
- A-Fib
AE of anticoagulants
- Hemorrhage
- bruising, bloody stools, bleeding gums, blood in urine, ecchyomosis
- thrombocytopenia
- back pain, joint pain
- bleeding into the abdomen or a joint
- GI distress
Special Concerns for rehab pts on anticoagulants
- know why your pt is on an anticoagulant
- while using this med, it is very important that one avoids contact sports and other activities that may cause you to be injured
- do not use with aspirin concurrently
- take special care in brushing teeth and in shaving
- soft toothbrush and floss gently
- best to use electric shaver over a blade
how do antiplatelet drugs work?
prevent platelets from clumping together to form a clot
- aspirin is a classic drug in this class
- may also be called blood thinners
what is an arrhytmia?
any significant deviation from normal cardiac rhythm
can result in:
- impaired pump function
- cardiac failure
- CVAs
- death
List several mechanisms for a cardiac arrhytmia
- abnormal pulse generation
- defects in SA or AV nodes
- ectopic foci
- abnormal pulse conduction
- abnormality in conduction pathway
- AV block
- Bundle branch block
- a combo of these
Drugs that treat arrhythmias
- Class I drugs → Na+ channel blockers
- Class II drugs → Beta blockers
- Class III drugs → prolong myocyte repolarization
- Class IV → Ca+ channel blockers
describe Class I anti-arrhythmic drugs
Na+ channel blockers
- normalize the rate of Na+ influx into the cell
- stabilize the membrane and reduce membrane excitability
- lidocaine is an example
describe Class II anti-arrhythmic drugs
Beta Blockers
- main stay of arrhythmia trx
- diminish the influence of the excitatory effects of the sympathetic NS
- decreases cardiac automaticity
- lengthens the effective refractory period resulting in a slower HR
T/F: being on a beta-blocker reduces the liklihood of a second MI
TRUE
describe Class III anti-arrhythmic drugs
Prolong myoctye repolarization
- inhibit K+ efflux
- slows/stabilizes HR
- used to treat ventricular arrhythmias
describe Class IV anti-arrhytmic drugs
Ca+ Channel Blockers
- normalize Ca++ entry into the channel thus controlling excitability and the conduction of cardiac tissue
- Verapamil, diltiazem
T/F: not all Ca++ channel blockers are effective in managing cardiac arrhythmias
TRUE
Statins are _________ lowering drugs
cholesterol
what drugs are used to treat hyperlipidemia?
HMG-CoA Reductase Inhibitors (Statins)
how do statins help treat hyperlipedmia?
- decreased cholesterol synthesis
- increased removal of LDLs from blood
- some can increase HDLs
- stabilize athersclerotic plaques
- reduce risk for an MI
AE of Statins
- Rhabdomyolysis
- Muscle pain
- liver damage → pt should have quarterly liver panels
- drug intolerance
- HA
- abdominal pain
- constipation
- Loss of Co Enzyme Q10