Download Chapter 19 Drugs Used to Treat Hypertension

 blood pressure is the amount of force exerted against the
walls of an artery by the blood
 blood pressure is controlled by:
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force of heart contractions
amount of blood pumped with each heartbeat (cardiac output)
how easily blood flows through the blood vessels
 blood pressure can change from minute to minute
**Factors affecting blood pressure listed in box 19-1 pg. 242**
 because BP can vary there are “normal” ranges:
 systolic pressure less than 120mm Hg (mm of mercury)
 diastolic pressure less than 80mm Hg
 hypertension: blood pressure is too high, systolic is 140mm
Hg or higher, or the diastolic is 90mm Hg or higher
 pre-hypertension: when systolic pressure is between 120-
139mm Hg. Or the diastolic pressure is 90mm Hg or higher
 persons with pre-hypertension will most likely develop
hypertension in the future
**see box 19-2 on pg. 243 for risk factors for hypertension**
 a person can have high BP for years without knowing, this is
why it’s called the “silent killer”
 hypertension usually is found when BP is measured
 signs and symptoms can develop, these include:
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headache
blurred vision
dizziness
nose bleeds
 hypertension over time can lead to:
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stroke
hardening of arteries
MI
heart failure
kidney failure
blindness
 the following lifestyle changes can help lower BP:
 diet low in fat and salt
 healthy weight
 regular exercise
 no smoking
 limiting alcohol and caffeine
 managing stress
 sleeping well
 drug therapy not necessary if lifestyle changes can lower BP
 can take months to control hypertension with meds
 many people require 2 or more meds to control BP
 Anti-hypertensive agents: drugs that reduce BP
 drug therapy depends on persons:
 age
 gender
 race
 other health problems
 risk factors
 previous therapy (what has/hasn’t worked)
 other meds
 cost
Delegation Guidelines
Drugs Used to Treat Hypertension:
Some drugs used to treat hypertension are give parenterally.
Because you do NOT give parenteral dose forms, they are not
included in this chapter. Should a nurse delegate the
administration of such to you, you must:
- remember that parenteral dosages are often very different
from dosages for other routes
- refuse the delegation. Make sure you explain why. Do NOT
just ignore the request. Make sure the nurse knows you
cannot give the drug and why
 Diuretics:
 drug that promotes the formation and excretion of urine
 diuretics:
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reduce the amount of extra-cellular fluid
promote sodium excretion
cause vaso-dilation of peripheral arterioles
 Diuretics are commonly prescribed alone or with other anti-
hypertensive drugs
 the risk of adverse effects is low
 they are inexpensive compared to other anti-hypertensive
drugs
 diuretics are discussed in ch. 22
 Beta-Adrenergic Blocking Agents:
 beta-blockers inhibit the hearts response to sympathetic
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nerve stimulation
they block beta receptors
beta receptors increase the heart rate
by blocking them the heart rate and cardiac output are
reduced, in turn reducing BP
beta blockers also block renin release from kidneys
renin is an enzyme that affects blood pressure
renin release results in processes that increase BP (vasoconstriction and sodium retention)
Assisting With the Nursing Process
Beta Blockers:
ASSESSMENT: measure BP, heart rate and rhythm, use apical pulse
PLANNING: see table 14-2 in ch. 14 for “Oral Dose Forms”
IMPLEMENTATION: see table 14-2 in ch. 14 for “Adult Dosage Range,”
onset of action is fairly rapid, it make take days/weeks to stabilize on lowest
dose needed. Angina and MI are risks if drug is suddenly stopped.
EVALUATION: most adverse effects are dose related, they resolve when
dosage is adjusted.
report and record:
- bradycardia, peripheral vaso-constriction (purple, mottled skin): nurse may
tell you to with-hold drug til MD can evaluate person
- broncho-spasm, wheezing: nurse may tell you to with-hold drug til MD can
evaluate person
- headache, weakness, decreased coordination, general apprehension, sweating,
hunger, or blurred/double vision: signal hypoglycemia
- edema, dyspnea, bradycardia, orthopnea: observe persons with heart failure
 Angiotensin-Converting Enzyme Inhibitors:
 known as ACE inhibitors, reduce BP by affecting the
renin-angiotensin-aldosterone system
 Renin: causes vasoconstriction and sodium retention
 Angiotensin: causes vasoconstriction, increased BP and the
release of aldosterone
 Aldosterone: causes the kidneys to retain sodium
 ACE inhibitors cont…
 the renin-angiotensin-aldosterone system regulates BP by:
 renin causes vaso-constriction and sodium retention (both increase BP), renin is
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secreted when BP, sodium levels or kidney blood flow is reduced
Angiotensinogen is secreted by liver, renin converts this to angiotensin I
the angiotensin-converting enzyme then converts angiotensin I to angiotensin II
Angiotensin II: acts on receptors in blood vessels to produce strong vaso-constriction
(which increases BP)
Angiotensin II also promotes aldosterone secretion, which causes sodium retention.
This causes body to retain water which increases BP
 ACE-inhibitors affect the angiotensin-converting enzyme, meaning the change of
angiotensin I- angiotensin II is inhibited
 When ACE-inhibitors are used:
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blood levels of angiotensin II are reduced, less vaso-constriction so BP is reduced
aldosterone levels are lower, less sodium and therefore less water retained, BP is reduced
Assisting With the Nursing Process
ACE-inhibitors:
ASSESSMENT: measure heart rate and rhythm, use apical pulse, measure BP
(supine/standing), measure intake/output, weigh daily, ask about bowel
elimination, ask if person has a cough
PLANNING: see table 19-1 (p. 245) for “Oral Dose Forms”
IMPLEMENTATION: see table 19-1 (p. 245) for “Adult Dose Range”
EVALUATION: report and record:
- hypotension with dizziness, tachycardia and fainting: may occur within first 3 hours
after several doses, more common if person also taking diuretics. Check person often until
BP is stable. Measure BP in standing/supine, provide for safety
- nausea, fatigue, headache, diarrhea: usually mild and tend to resolve
- swelling of face, eyes, lips, tongue, difficulty breathing: signals drug allergy, alert
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nurse at once, do not give next dose unless nurse approves
sore throat, fever, jaundice, weakness: may signal changes in white blood cells
changes in alertness, disorientation, confusion,: provide for safety
changes in muscle strength, muscle cramps, tremors, nausea, drowsiness, anxiety,
lethargy: may signal potassium level changes
chronic, dry, non-productive, persistent cough: may appear 1 week to 6 months after
the start of therapy
 Angiotensin II Receptor Blockers (ARB’s):
 ARBs bind to angiotensin II receptor sites, and block binding
 sights are located in blood vessels, brain, heart, kidneys, adrenal
glands
 by blocking these sites ARBs lower BP because:
 vaso-constriction does not occur, blood vessels do NOT narrow
 aldosterone secretion is blocked, this prevents sodium retention and
body does NOT retain excess water
 ARBs may be used alone to control BP, or taken with diuretic
 BP lowering effect is seen within 1 week, may take 3-6 weeks for
full therapeutic effect.
Assisting With the Nursing Process
ARBs:
ASSESSMENT: measure heart rate and rhythm, measure BP
(supine/standing), measure intake/output, weigh daily, ask about
bowel elimination, ask about GI symptoms
PLANNING: see table 19-2 (p. 246) for “Oral Dose Forms”
IMPLEMENTATION: see table 19-2 (p. 246) for “Adult Dose Range”
EVALUATION: report and record:
- headache, heartburn, indigestion, cramps, diarrhea: mild and
tend to resolve
- hypotension with dizziness, weakness and fainting: may occur within
first 3 hours after several doses, more common if person also taking diuretics.
Check person often until BP is stable. Measure BP in standing/supine, provide
for safety
- changes in alertness, disorientation, confusion,: provide for safety
- changes in muscle strength, muscle cramps, tremors, nausea,
drowsiness, anxiety, lethargy: may signal potassium level changes
Aldosterone Receptor Blocking Agent:
 there is a review of renin-angiotensin-aldosterone system p. 246 or
slide #12
 this agent blocks aldosterone receptors, prevents sodium from
being re-absorbed.
 can be used with other anti-hypertensive drugs
Assisting With the Nursing Process
eplerenone (Inspra):
 ASSESSMENT: measure BP (supine/standing), measure intake/output,
measure weight daily, ask about bowel elimination patterns
 PLANNING: oral dose forms: 25 and 50mg tablets
 IMPLEMENTATION: the initial dose is 50mg daily, with or without food,
the full therapeutic effect should be seen within 4 weeks, dosage may be
increased to 50mg 2x/day
 EVALUATION: report and record:
- nausea, fatigue, headache, diarrhea: tend to be mild and resolve
- hypotension, dizziness, weakness, and fainting: more common in people who
also receive diuretic. check person often until BP is stable. Measure BP in
supine/standing, provide for safety
- changes in muscle strength, muscle cramps, tremors, nausea, drowsiness,
anxiety, lethargy: may signal changes in potassium
- intake and output: used to monitor kidneys
- anorexia, nausea, vomiting, jaundice: may signal liver toxicity
Calcium Ion Antagonists:
 to understand how these drugs work you first need to know
the following terms:
 ion: an atom with an electrical charge
 atom: smallest part of an element
 element: a simple substance that cannot be broken down into
another substance
 calcium: an element, body needs calcium ions for transmission
of nerve impulses, muscle contractions, blood clotting, heart
functions
 calcium channel: the way calcium ions pass through cell
membrane
 antagonist: exerts the opposite action to that of another, or it
competes for the same receptor sites
Calcium Ion Antagonists cont…
 calcium ion antagonists inhibit the movement of calcium
ions across a cell membrane.
 also called calcium antagonists and calcium channel blockers
 they relax the smooth muscle of blood vessels, which results
in vaso-dilation, and reduces BP
 these are also used to treat dysrhythmias (ch. 20) and angina
(ch.21)
Assisting With the Nursing Process
calcium ion antagonists:
ASSESSMENT: measure heart rate/rhythm, use apical pulse,
measure BP (standing/supine), measure intake/output, measure
weight daily
PLANNING: see table 19-3 (pg. 247) for “Oral Dose Forms”
IMPLEMENTATION: see table 19-3 (pg. 247) for “Adult Dosage
Range”
EVALUATION: report and record:
- hypotension and fainting: may occur in first week, decline when
dosage is stabilized, provide for safety
- edema: measure weight daily, measure intake/output
Alpha-1 Adrenergic Blocking Agents:
 alpha-1 receptors in nervous system cause blood vessels to
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constrict
alpha-1 adrenergic blocking agents block alpha-1 receptors
by blocking receptors that cause blood vessels to constrict
(narrow) the blood vessels dilate (widen). this dilation lowers BP
may be used alone or with other anti-hypertensive drugs
alpha-1 blockers also are used to treat benign prostatic hyperplasia
(ch. 29) they relax smooth muscle of bladder and prostate
Assisting With the Nursing Process
Alpha-1 Adrenergic Blocking Agents:
ASSESSMENT: measure heart rate/rhythm, use apical pulse, measure BP
(standing/supine)
PLANNING: see table 19-4 (pg. 249) for “Oral Dose Forms”
IMPLEMENTATION: see table 19-4 (pg. 249) for “Adult Dosage Range”
EVALUATION: report and record:
- hypotension with dizziness, tachycardia and fainting: may occur within
15-90 minutes after the first several dosages. More common in
persons who receive diuretic. check person until BP is stable.
provide for safety
- drowsiness, headache, dizziness, weakness, lethargy: may resolve with
continued therapy
Central-Acting Alpha-2 Agonists:
 alpha-2 receptors prevent the further release of norepineprine
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(norepi stimulates sympathetic nervous system). The
sympathetic nervous system speeds up body functions
agonist is a drug that acts on a certain type of cell, produces a
predictable response
Central-acting alpha-2 agonists stimulate the alpha-adrenergic
receptors in brainstem. this reduces sympathetic nervous
system activity
heart rate and peripheral vascular resistance are reduced, resulting
in lower BP
alpha-2 agonists are using in combination with other antihypertensive agents
Assisting With the Nursing Process
alpha-2 agonists:
ASSESSMENT: measure heart rate/rhythm, use apical pulse, measure BP
(standing/supine), observe for signs/symptoms of depression (ch. 15),
observe persons sleep patterns (ch. 14)
PLANNING: see table 19-5 (pg. 250) for “Oral Dose Forms”
IMPLEMENTATION: see table 19-5 (pg. 250) for “Adult Dosage Range”, if
transdermal patch becomes loose apply adhesive overlay directly over
patch
EVALUATION: report and record:
- drowsiness, dizziness, dry mouth: tend to resolve, provide for safety,
provide oral hygiene and offer fluids as directed by nurse and care plan
- dark urine: this is harmless
- depression: see ch.15 for signs/symptoms
- rash: may occur at site of transdermal patch
Peripheral-Acting Adrenergic Antagonists:
 these lower norepinephrine levels
 these include:
 guanadrel (Hylorel)
 guanethidine sulfate (Ismelin)
 reserpine (Serpasil)
Peripheral-Acting Adrenergic Antagonists cont…
guanadrel (Hylorel):
- causes release of norepinephrine from nerve endings
- this causes smooth msucles of the blood vessels to relax
- peripheral vascular resistance is decreased, BP lowers
- venous blood return to heart decreases, this can lead to fluid
retention and edema
- used with diuretics
Assisting With the Nursing Process
guanadrel (Hylorel):
ASSESSMENT: measure BP (standing/supine), measure weight daily,
measure input/output
PLANNING: oral dose form: 10 and 25mg tablets
IMPLEMENTATION: initial dose is 10mg daily, divided into 2 doses.
Dosage is adjusted weekly to monthly PRN. Usual dose range is 20-75mg
daily in 2-3 divided doses
EVALUATION: report and record:
- orthostatic hypotension: BP is measured (supine/standing),
provide for safety
- sedation and lethargy: may occur when therapy is started or if dose
is increased, tends to subside
- edema: measure weight daily, measure intake/output, check legs for
swelling, observe for dyspnea, wheezing and frothy or
blood-tinged sputum: see signs/symptoms of heart failure (Ch. 21)
guanethidine sulfate (Ismelin):
 depletes norepinephrine from the nerves
 inhibits the release of norepinephrine in response to
sympathetic nerve stimulation
 used with diuretics
 BP decreases because:
 cardiac output is less
 vaso-constriction is blocked, peripheral vascular resistance is
decreased
Assisting With the Nursing Process
guanethidine sulfate (Ismelin):
ASSESSMENT: measure BP (standing/supine), measure weight daily, measure
input/output
PLANNING: oral dose form: 10 and 25mg tablets
IMPLEMENTATION: initial dose is 10mg daily. Dosage is increased 10mg every 57 days PRN. Usual dosage range is 25-50mg, or more.
EVALUATION: report and record:
- orthostatic hypotension: BP is measured (supine/standing),
provide for
safety
- light-headedness, weakness: because blood vessels dilate, blood can collect in
the lower legs. This causes reduced blood flow to the brain. Symptoms often
disappear during day. Have person sit for a few minutes after lying down. Have
them perform leg/foot/toe exercises before standing
- edema: measure weight daily, measure intake/output, check legs for swelling,
observe for dyspnea, wheezing and frothy blood-tinged sputum (see ch.21 for
sigs/symptoms of heart failure)
reserpine (Serpasil):
 reduces norepinephrine levels in peripheral nerve endings, the
brain and other organs
 heart rate slows and peripheral vascular resistance decreases
 has a long duration of action
 may take 2-6 weeks before desired therapeutic effect is seen
Assisting With the Nursing Process
reserpine (Serpasil):
ASSESSMENT: measure BP (standing/supine), measure weight daily,
measure input/output, observe for signs/symptoms of depression (ch.
15), observe persons sleep patterns (ch. 14)
PLANNING: oral dose form: o.1 and 0.25mg tablets
IMPLEMENTATION: initial dose is .5mg daily, for 1-2 weeks. Usual dosage
range is 0.1-0.25mg daily
EVALUATION: report and record:
- nasal congestion: tends to resolve with continued therapy
- diarrhea, stomach cramps: tends to resolve with continued
therapy
- depression: see ch.15 for signs/symptoms
- nightmares, insomnia: drug therapy may need to be changed
- stomach burning or pain, nausea, vomiting: ulcers a risk
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Direct Vaso-Dilators:
act directly on the smooth muscles of arterioles
arterioles relax
reduces peripheral vascular resistance
BP lowers
these drugs include:
 hydralazine (Apresoline)
 minoxidil (Loniten)
hydralazine (Apresoline)
 reduces peripheral vascular resistance causing lower BP
 the following increase:
 cardiac out put
 renin release (p. 244)
 sodium and water retention
 used in combination with diuretics and other drugs
Assisting With the Nursing Process
hydralazine (Apresoline)
ASSESSMENT: measure heart rate/rhythm with apical pulse, measure BP
(standing/supine), measure weight daily, measure input/output
PLANNING: oral dose form: 10, 25, 50, 100mg tablets
IMPLEMENTATION: initial dose 10mg 4x/day for first 2-4 days, then
25mg are give 4x/day. Second week the dosage is increased to 50mg
4x/day as BP is brought under control
EVALUATION: report and record:
- nausea, dizziness, tachycardia, numbness and tingling in the legs, nasal
congestion: dosage may need adjusted
- orthostatic hypotension: provide for safety
- fever, chills, joint and muscle pain, skin problems: may signal pain in
white blood cells
minoxidil (Loniten):
 causes smooth muscles of arterioles to relax
 reduces peripheral vascular resistance causing lower BP
 the following increase:
 cardiac out put
 renin release (p. 244)
 sodium and water retention
 used in combination with diuretics and other drugs
Assisting With the Nursing Process
minoxidil (Loniten):
ASSESSMENT: measure heart rate/rhythm with apical pulse, measure BP
(standing/supine), measure weight daily, measure input/output
PLANNING: oral dose form: 2.5 and 10mg tablets
IMPLEMENTATION: initial dose 5mg daily, dosage may increase gradually after
at least 3 days intervals to 10mg, 20mg and then 40mg daily in 1-2 doses. Dose
should not exceed 100mg daily.
EVALUATION: report and record:
- hair growth: seen in men and women. Fine body hair becomes long, thick and
dark. Occurs on face first within 3-6 weeks. later seen back, arms, legs and scalp
- sodium and water retention: observe for swelling of face, hands, ankles
- increased resting pulse rate
- light-headedness, fainting, dizziness: provide for safety
- orthostatic hypotension: provide for safety
- swelling of breasts in men
- signs and symptoms of heart failure (ch. 21)
 some persons take more than 1 anti-hypertensive drug,
2nd drug is often a diuretic. A combination drug may
be ordered
 see table 19-6 pg. 253