NUR120 Week 2 Pharmacology and the nursing process Lilley
chapters 22 26 27 with Complete Solutions
Chapter 22 Antihypertensive Drugs
Hypertension A common, often asymptomatic disorder in which systolic blood
pressure persistently exceeds:
Patients 60+:Systolic 150 and/or diastolic 90
Patients younger than 60, with CKD or DM: Systolic 140 and/or diastolic 90.
Essential hypertension Elevated systemic arterial pressure for which no cause can
be found; also called primary or idiopathic hypertension.
Secondary hypertension High blood pressure caused by another disease such as
renal, pulmonary, endocrine, or vascular disease.
Prodrug A drug that is inactive in its given form and must be metabolized to its
active form in the body, generally by the liver, to be effective.
Hypertension is a major risk factor for coronary artery disease, cardiovascular
disease (CVD), and death resulting from cardiovascular causes. It is the most
important risk factor for stroke and heart failure, and it is also a major risk factor for
renal failure and peripheral vascular disease.
The goal of antihypertensive therapy is the reduction of cardiovascular and renal
morbidity and mortality. Adequately treating hypertension can prevent or delay
CVD.
Blood pressure is determined by the product of cardiac output and systemic vascular
resistance. SVR is the resistance to blood flow that is determined by the diameter of
the blood vessel and the vascular musculature.
Seven main categories of drugs used to treat hypertension:
Diuretics
Adrenergic drugs
Direct vasodilators
Angiotensin-converting enzyme (ACE) inhibitors
Angiotensin receptor blockers (ARBs)
Calcium channel blockers (CCBs)
Direct renin inhibitors
*All of these drugs (except diuretics) have some vasodilatory action.
Adrenergic drugs
Mechanism of action of adrenergic drugs
,Physiologic activity at adrenergic receptors is stimulated by norepinephrine,
epinephrine, and adrenergic agonists and is inhibited by antiadrenergic (adrenergic
blockers; i.e., alpha or beta receptor blockers). These mechanisms are explained in
depth in the Week 1 review (Chapters 18 and 19).
There are several categories of adrenergic antihypertensives:
Alpha 2 agonists (centrally acting)
The centrally acting adrenergic drugs clonidine and methyldopa work by stimulating
the alpha2-adrenergic receptors in the brain. These receptors are unique in that
,receptor stimulation actually reduces sympathetic outflow. This results in a lack of
norepinephrine production, which reduces blood pressure. Stimulation of the alpha2
receptors also affects the kidneys, reducing the activity of renin, in turn inhibiting
the RAAS, thus preventing the activation of angiotensin II- a vasoconstrictor.
Alpha 1 blockers (“opsins”) (peripherally acting)
Blockade of alpha 1 agonist decreases blood pressure by dilating arteries and veins,
which reduces peripheral vascular resistance. The alpha1 blockers also increase
urinary flow rates and decrease outflow obstruction by preventing smooth muscle
contractions in the bladder neck and urethra. This makes them the drugs of choice
for treating BPH.
Beta blockers (“looks”) (peripherally acting)
Their antihypertensive effects are related to their reduction of the heart rate
through beta1 receptor blockade. Furthermore, beta blockers also cause a reduction
in the secretion of renin, which in turn reduces angiotensin II-mediated
vasoconstriction and aldosterone-mediated volume expansion.
Dual action alpha 1 and beta blockers (“lolls”) (peripherally acting)
These drugs act at the heart and blood vessels. They have the dual antihypertensive
effects of reduction in heart rate (beta1 receptor blockade) and vasodilation (alpha1
receptor blockade). Examples are Carvedilol and Labetalol.
Indications of adrenergic drugs
Mainly the treatment of hypertension. Various forms of glaucoma may also respond
to treatment with some of these drugs. The alpha1 blockers doxazosin, prazosin, and
terazosin have been used to relieve the symptoms associated with BPH.
The alpha2 agonist Clonidine is used to treat opioid withdrawals; and Methyldopa
(also an alpha2 agonist) is used to treat hypertension in pregnant women.
Contraindications to the use of adrenergic drugs
Known drug allergy, heart failure, concurrent use of monoamine oxidase inhibitors,
peptic ulcer, and severe liver or kidney disease. Asthma may also be a
contraindication to the use of any non-cardio selective beta blocker (beta 2 blockade
causes bronchoconstriction).
Adverse effects of adrenergic drugs
The most common adverse effects of adrenergic drugs are bradycardia with reflex
tachycardia, postural and postexercise hypotension, dry mouth, drowsiness,
dizziness, depression, edema, constipation, and sexual dysfunction.
Alpha1 blockers are notorious for causing orthostatic hypotension.
First-dose syncope is a situation in which the hypotensive effect is severe enough to
cause the patient to lose consciousness with even the first dose of medication.
Also, abrupt discontinuation of some of these drugs can result in rebound
, hypertension
(sudden very high BP).
Finally, nonselective blocking drugs can cause bronchoconstriction.
chapters 22 26 27 with Complete Solutions
Chapter 22 Antihypertensive Drugs
Hypertension A common, often asymptomatic disorder in which systolic blood
pressure persistently exceeds:
Patients 60+:Systolic 150 and/or diastolic 90
Patients younger than 60, with CKD or DM: Systolic 140 and/or diastolic 90.
Essential hypertension Elevated systemic arterial pressure for which no cause can
be found; also called primary or idiopathic hypertension.
Secondary hypertension High blood pressure caused by another disease such as
renal, pulmonary, endocrine, or vascular disease.
Prodrug A drug that is inactive in its given form and must be metabolized to its
active form in the body, generally by the liver, to be effective.
Hypertension is a major risk factor for coronary artery disease, cardiovascular
disease (CVD), and death resulting from cardiovascular causes. It is the most
important risk factor for stroke and heart failure, and it is also a major risk factor for
renal failure and peripheral vascular disease.
The goal of antihypertensive therapy is the reduction of cardiovascular and renal
morbidity and mortality. Adequately treating hypertension can prevent or delay
CVD.
Blood pressure is determined by the product of cardiac output and systemic vascular
resistance. SVR is the resistance to blood flow that is determined by the diameter of
the blood vessel and the vascular musculature.
Seven main categories of drugs used to treat hypertension:
Diuretics
Adrenergic drugs
Direct vasodilators
Angiotensin-converting enzyme (ACE) inhibitors
Angiotensin receptor blockers (ARBs)
Calcium channel blockers (CCBs)
Direct renin inhibitors
*All of these drugs (except diuretics) have some vasodilatory action.
Adrenergic drugs
Mechanism of action of adrenergic drugs
,Physiologic activity at adrenergic receptors is stimulated by norepinephrine,
epinephrine, and adrenergic agonists and is inhibited by antiadrenergic (adrenergic
blockers; i.e., alpha or beta receptor blockers). These mechanisms are explained in
depth in the Week 1 review (Chapters 18 and 19).
There are several categories of adrenergic antihypertensives:
Alpha 2 agonists (centrally acting)
The centrally acting adrenergic drugs clonidine and methyldopa work by stimulating
the alpha2-adrenergic receptors in the brain. These receptors are unique in that
,receptor stimulation actually reduces sympathetic outflow. This results in a lack of
norepinephrine production, which reduces blood pressure. Stimulation of the alpha2
receptors also affects the kidneys, reducing the activity of renin, in turn inhibiting
the RAAS, thus preventing the activation of angiotensin II- a vasoconstrictor.
Alpha 1 blockers (“opsins”) (peripherally acting)
Blockade of alpha 1 agonist decreases blood pressure by dilating arteries and veins,
which reduces peripheral vascular resistance. The alpha1 blockers also increase
urinary flow rates and decrease outflow obstruction by preventing smooth muscle
contractions in the bladder neck and urethra. This makes them the drugs of choice
for treating BPH.
Beta blockers (“looks”) (peripherally acting)
Their antihypertensive effects are related to their reduction of the heart rate
through beta1 receptor blockade. Furthermore, beta blockers also cause a reduction
in the secretion of renin, which in turn reduces angiotensin II-mediated
vasoconstriction and aldosterone-mediated volume expansion.
Dual action alpha 1 and beta blockers (“lolls”) (peripherally acting)
These drugs act at the heart and blood vessels. They have the dual antihypertensive
effects of reduction in heart rate (beta1 receptor blockade) and vasodilation (alpha1
receptor blockade). Examples are Carvedilol and Labetalol.
Indications of adrenergic drugs
Mainly the treatment of hypertension. Various forms of glaucoma may also respond
to treatment with some of these drugs. The alpha1 blockers doxazosin, prazosin, and
terazosin have been used to relieve the symptoms associated with BPH.
The alpha2 agonist Clonidine is used to treat opioid withdrawals; and Methyldopa
(also an alpha2 agonist) is used to treat hypertension in pregnant women.
Contraindications to the use of adrenergic drugs
Known drug allergy, heart failure, concurrent use of monoamine oxidase inhibitors,
peptic ulcer, and severe liver or kidney disease. Asthma may also be a
contraindication to the use of any non-cardio selective beta blocker (beta 2 blockade
causes bronchoconstriction).
Adverse effects of adrenergic drugs
The most common adverse effects of adrenergic drugs are bradycardia with reflex
tachycardia, postural and postexercise hypotension, dry mouth, drowsiness,
dizziness, depression, edema, constipation, and sexual dysfunction.
Alpha1 blockers are notorious for causing orthostatic hypotension.
First-dose syncope is a situation in which the hypotensive effect is severe enough to
cause the patient to lose consciousness with even the first dose of medication.
Also, abrupt discontinuation of some of these drugs can result in rebound
, hypertension
(sudden very high BP).
Finally, nonselective blocking drugs can cause bronchoconstriction.
