Drugs Affecting the Cardiovascular Systems Flashcards
what are the 4 factors that regulate cardiovascular disease?
- Autonomic NS
- Kidneys
- Heart
- Blood volume & composition
how is the autonomic NS involved in regulation of cardiovascular disease?
from the innervations of the parasympathetic and sympathetic divisions to the heart, BV, kidneys, and adrenal glands
how are the kidneys involved in regulation of cardiovascular disease?
maintenance of cardiac output by excretion & reabsorption of ions and water
how is the heart involved in regulation of cardiovascular disease?
through its effects on rate & force of contraction through the intrinsic NS
how is blood volume and composition involved in regulation of cardiovascular disease?
water and electrolyte balance
hypertension =
systolic pressure > 140 mm Hg
diastolic pressure > 90 mm Hg
what type of hypertension composes up to 90% of cases?
primary hypertension
primary hypertension’s specific cause is
unknown
BP =
cardiac output (CO) X Peripheral Vascular Resistance (PVR)
what is the cause of secondary hypertension
causative basis for elevation in pressure
eclampsia of pregnancy, renal artery disease, pheochromocytoma
CO=
heart rate (HR) X stroke volume (SV)
there is a _________ relationship between vascular resistance and blood pressure
direct
vasoconstriction can be described as a
decrease in lumen size
vasoconstriction will __________ resistance to blood flow therefore increasing _____________ ____________
- increase
- blood pressure
vasodilation can be described as an
increase in lumen size
vasodilation decreases resistance to __________ _______ and in turn _______ BP
- blood flow
- decreases
what are the 6 categories of antihypertensive agents?
- adrenergic agents
- angiotensin-converting enzyme inhibitors
- angiotensin II receptor blockers
- calcium channel blockers
- diuretics
- vasodilators
alpha 1 blockers are peripheral acting agents that block the
adrenergic agents
vasoconstricting effects through alpha 1 receptors
beta 1 blockers are cardio selective agents that
adrenergic agents
decrease the force of contraction in the heart
What may be a consequence of given a “non-selective” beta blocker to a patient that may also have asthma?
BAD RESULT
- severe bronchospasm
- fatalitites
- bronchoconstriction
- asthma exacerbations
give an example of alpha 2 agonists
clonidine
alpha 2 agonists stimulate what? to decrease what?
adrenergic agents
stimulate: alpha 2 receptors
decrease: sympathetic outflow from the CNS
ACE inhibitors block
angiotensin converting enzyme
the conversion of angiotensin 1 to angiotensin II
angiotensin II is a potent
vasoconstrictor
angiotensin II stimulates the release of
aldosterone
aldosterone is a vasoconstrictor that promotes the
reabsorption of H2O and Na in the renal tubules
what is the MOA of angiotensin II receptor blockers?
to block the receptors that receive AII inhibiting vasoconstriction and the release of aldosterone
calcium channel blockers cause
smooth muscle relaxation
how do calcium channel blockers cause smooth muscle relaxation?
by blocking the binding of calcium to its receptors
vasodilators are
rapid acting
how does calcium channel blockers affect PVR and BP?
decreases both of them
vasodilators are powerful
antihypertensives
vasodilators directly relaxes
smooth muscle
what are the 4 categories of diuretics based on their pharmacodynamics?
- loop diuretics
- osmotic diuretics
- potassium-sparing diuretics
- thiazide diuretics
diuretics decrease the
plasma and extracellular fluid volumes
how do diuretics decrease the plasma and extracellular fluid volumes?
by increasing the rate of urine formation
what is the result of diuretics?
decrease cardiac output and blood pressure
loop diuretics are aka
lasix
loop diuretics inhibit
sodium and chloride resorption
loop diuretics increase
renal prostaglandins
an increase in renal prostaglandins results in
- BV dilation
- decreased PVR
peripheral vascular resistance
there is a tendency to loose _________ during excretion with loop diuretics.
calcium
what is an example of osmotic diuretics?
mannitol
osmotic diuretics do NOT
- interact w/ receptors
- block renal transport mechanisms
osmotic diuretics produce an
osmotic gradient
how do osmotic diuretics increase urine output?
by pulling water into the tubule system of the nephrons
potassium-sparing diuretics prevent
potassium from being pumped into the tubules and excreted in the final urine product
potassium-sparing diuretics have a….
this is why they are used in combination with other diuretics
weak overall effect
thiazide diuretics inhibit the
reabsorption of sodium and chloride
with thiazides there is a
decreased loss of calcium in the excretion
where sodium goes…
water follows
antiarrhythmic drugs are drugs used for the
treatment and prevention of cardiac rhythm disturbances
action potential pathway describes the flow of
depolarization through the intrinsic NS of the heart
describe the pathway known as action potential “Super Highway”
sinoatrial node -> atrioventricular node -> bundle of His -> L&R bundle branches -> purkinje network & papillary muscles
ALL antiarrhythmic drugs have the potential to they themselves…
produce arrhythmias
what are 4 common antiarrhythmic drugs
- sodium channel blockers
- beta blockers
- drugs prolonging the AP from the SA to AV node
- calcium channel blockers
sodium channel blockers MOA is to
decrease the AP or electrical conductance within the heart
beta blocker’s MOA is to
reduce stimulation to the sympathetic NS
calcium channel blockers are commonly used for what conditions?
- arrhythmias
- tachycardia
drugs that prolong the AP from the SA to the AV node are commonly used for
- atrial arrhythmias
- ventricular tachycardia
calcium channel blocker’s MOA is to
decrease intracellular calcium that is required for cardiac muscle contraction
define heart failure
a reduction in cardiac output resulting in a loss of blood pressure
with heart failure there is an initial
compensatory response
the compensatory response in heart failure is accompanied by
elevated sympathetic NS activity
an elevation in SNS activity increases the
rate and force of contraction in the heart by stimulating beta1, 2, and alpha 1 receptors
long term SNS produces…
hyperadrenergic state
a hyperadrenergic state may lead to
- irreversible myocyte damage
- fibrotic buildup
- death of cardio-myocytes (myocardial infarction)
what are the 6 different pharmacological treatment options for heart failure
- ACE inhibitors
- angiotensin receptor blockers
- beta-adrenergic blockers
- aldosterone antagonists
- diuretics
- phosphodiesterase inhibitors
what is the MOA of beta-adrenergic blockers
to reverse the effect of SNS activity and reduce cardiac workload
what is the MOA of aldosterone antagonists
to inhibit sodium retention in the kidneys and sympathetic activity promoted by aldosterone binding to its receptors
what is the MOA for phosphodiesterase inhibitors?
increase cAMP in cell and produce a positive inotropic force of contraction
