1. Chapter 19 Drugs Used to Treat Hypertension

2. blood pressure is controlled by:
blood pressure is the amount of force exerted against the walls of an artery by the blood
blood pressure is controlled by:
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**

3. 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 mm 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**

4. hypertension usually is found when BP is measured
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:
headache
blurred vision
dizziness
nose bleeds
hypertension over time can lead to:
stroke
hardening of arteries MI
heart failure
kidney failure
blindness

5. 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

6. 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

7. 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

8. drug that promotes the formation and excretion of urine diuretics:
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

9. Beta-Adrenergic Blocking Agents:
beta-blockers inhibit the hearts response to sympathetic 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 (vaso- constriction and sodium retention)

10. 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

11. 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

12. ACE inhibitors cont…
the renin-angiotensin-aldosterone system regulates BP by:
renin causes vaso-constriction and sodium retention (both increase BP), renin is 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:
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

13. 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 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

14. 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.

15. 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

16. 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

17. 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

18. 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

19. 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)

20. 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

21. Alpha-1 Adrenergic Blocking Agents:
alpha-1 receptors in nervous system cause blood vessels to 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

22. 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 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

23. Central-Acting Alpha-2 Agonists:
alpha-2 receptors prevent the further release of norepineprine (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 anti- hypertensive agents

24. 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

25. Peripheral-Acting Adrenergic Antagonists:
these lower norepinephrine levels
these include:
guanadrel (Hylorel)
guanethidine sulfate (Ismelin)
reserpine (Serpasil)

26. 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

27. 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)

28. 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

29. 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 5-7 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)

30. 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

31. 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 mg 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

32. 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)

33. 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

34. 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

35. 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

36. 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)

37. 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