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Medications to Treat Hypertension
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Kristen L. Mauk, PhD RN CRRN-A APRN BC
Nearly 65 million American adults, or one in
three persons, have hypertension. Often called
the “silent killer” because of the lack of early
symptoms, high blood pressure contributed to
the death of more than 52,600 people in 2003
(American Heart Association, 2005). The death
rate for African Americans, both men and women,
is significantly higher than for Caucasians. Hypertension also remains the number-one risk factor
for stroke, a leading cause of death and disability
throughout the world.
Hypertension is defined by the American
Heart Association as a blood pressure of 140/90
or higher. The vast majority of hypertension
has no identifiable cause but is manageable
by lifestyle changes and medications. The
purpose of this article is to discuss the common
medications used in treatment of hypertension.
The most recent guidelines for treating
hypertension provide four basic strategies
to manage and prevent complications. First,
identify prehypertenion and begin lifestyle
changes early. Prehypertension is defined as a
blood pressure of 130–139 mm Hg systolic and
80–89 mm Hg diastolic. Persons with prehypertension are more likely to become hypertensive
than those with lower blood pressures. Second,
even for patients over the age of 50, treat a
systolic blood pressure over 140 mm Hg.
Previous guidelines allowed older adults more
flexibility in the systolic reading if the diastolic
was within normal limits. New research suggests
that deaths could be avoided by initiating
treatment earlier. Third, the use of more than
one medication is advisable. “Using more than
one drug to treat most patients will be key to
improving blood pressure control rates. Patients
and physicians need to begin the drug treatment
process with an open mind, using as much
medication as necessary to achieve goal blood
pressure” (Jones, 2003).
A few significant classes of medications are
commonly used in treatment of hypertension.
These include diuretics, beta-blockers, ACE
inhibitors, angiotensin II receptor blockers,
calcium channel blockers, and central alpha
agonists. Table 1 provides a summary of the
common medications used under each class.
Common Medications
Diuretics
Diuretics help older adults decrease water
and sodium retention. The rule for dosing in the
elderly is start low and go slow. Diuretics have
fewer adverse reactions for older adults and
reduce both morbidity and mortality associated
with poor circulation (Kennedy-Malone,
Fletcher, & Plank, 2000). Hydrochlorthiazide
12.5–25 mg/day is a commonly prescribed
treatment. Furosemide (Lasix) may be used for
those with impaired renal function. Side effects
from diuretics include weakness, leg cramps,
fatigue, and dizziness. Potassium supplements
may be needed. Nurses should educate patients
to take diuretics in the morning, because an
increase in urination is likely to occur.
Beta-Blockers
Beta-blockers reduce the heart rate and lower
cardiac output. Medications such as atenolol
(Tenormin) and metoprolol (Lopressor, Toprol
XL) are common. They are the drug of choice for
patients with a history of angina or heart attack,
but are contraindicated in those with chronic
obstructive pulmonary disease (COPD). Betablockers are often used in combination with
thiazide diuretics, particularly with older adults.
They may be manufactured in combination with
diuretics in medications such as Inderide
(propranolol and hydrochlorothiazide). When
combined with calcium channel blockers, betablockers may cause bradycardia. Major side
effects from beta-blockers include fatigue,
decreased exercise tolerance, depression, impotence, glucose intolerance, and increased triglycerides (The Washington Manual: Geriatrics
Subspecialty Consult, 2005). Nurses should
caution patients to report a pulse slower than 60
beats per minute (unless otherwise directed by
the physician) and never to abruptly discontinue
these medications. In the hospital setting,
monitor blood pressure and pulse prior to
administering beta-blockers. Nurses should also
be alert that beta-blockers can mask hypoglycemia in diabetics and exacerbate wheezing in
those with asthma.
ACE Inhibitors
Angiogenesis-converting enzyme (ACE)
inhibitors decrease resistance of the blood
vessels by interfering with the body’s production
of angiotensin (a vessel constrictor), lowering
the levels of this chemical to allow the arteries
to relax. ACE inhibitors are preferred for patients
with heart failure and as a first-line treatment
to reduce the risk of nephropathy for those
with diabetes. Doses should be titrated slowly
over a period of weeks. ACE inhibitors are
also frequently used with diuretics or calcium
channel blockers for combination therapy. Side
effects to particularly note include renal function
changes, electrolyte imbalance, cough, dizziness,
weakness, and orthostatic hypotension.
Angiotensin-II Receptor Antagonists
Angiotensin-II receptor blockers (ARBs), or
antagonists, block the effects of angiotensin,
producing effects similar to the ACE inhibitors.
The mechanism of action is slightly different,
in that the effects of angiotensin are prevented
from ever effecting the heart or blood vessels by
blocking the A-II receptors, thereby prohibiting
elevation of blood pressure. A-II receptor
antagonists may also used in combination with
diuretics for better blood pressure control. The
side effects with these medications are fewer
than for the other drug classes used to treat
hypertension. The incidence of serious side
effects is rare, and the dry cough seen with ACE
inhibitors occurs significantly less with ARBs.
Calcium Channel Blockers
Calcium channel blockers (CCBs), also
known as calcium antagonists, reduce heart
rate and relax blood vessels by interfering
with the movement of calcium in the heart
and associated arteries. By blocking the
entry of calcium into specific cells, calcium
channel blockers dilate the arteries and thus
decrease the workload on the heart. For this
reason, they are also used to treat angina and
some dysrhythmias. Common medications in
this category include diltiazem (Cardizem),
amlodipine (Norvasc), and verapamil (Calan).
Side effects of CCBs are constipation,
headache, nausea, rash, edema, drowsiness,
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June/July 2006
• ARNNetwork
Medications to Treat Hypertension Continued from page 5
dizziness, and hypotension. Educate patients
to take these medications before meals and as
ordered. Patients should also be encouraged
to limit caffeine intake while taking CCBs to
decrease the risk of adverse effects. Blood work
should be monitored carefully for therapeutic
levels. Because constipation may be a common
side effect of certain CCBs, patients should eat a
diet high in fiber and drink plenty of fluids.
Alpha-Blockers
Alpha blockers, also called alpha-adrenergic
antagonists, block the effects of adrenalinetype chemicals on alpha receptors to prevent a
rise in blood pressure. They include commonly
used medications such as doxazosin mesylate
(Cardura) and prazosin hydrochloride
(Minipress). Side effects include increased heart
rate, dizziness, and orthostatic hypotension.
Alpha- and beta-blockers are often combined in
medications such as carvedilol (Coreg). Patients
on these medications should be cautioned to
change positions slowly, use fall-prevention
strategies, and be aware of potential side effects.
Central Alpha Agonists
Alpha agonists, such as clonidine hydrochloride
(Catapres) and methyldopa (Aldomet), lower
blood pressure by stimulating alpha receptors in
the brain that dilate peripheral arteries, thereby
decreasing resistance and increasing blood flow.
Central alpha agonists are usually prescribed when
other antihypertensive medications have been
ineffective. The side effects may include dry mouth
and fatigue.
Nursing Implications
Rehabilitation nurses can prevent, diagnose
and treat hypertension by recognizing risk
factors and identifying those persons in need of
screening. Common risk factors for hypertension
include family history, African American race,
male gender, increased age, sedentary lifestyle,
high-sodium diet, diabetes or renal disease,
high alcohol consumption, obesity, and some
medications.
10 ARNNetwork • June/July 2006
In addition to antihypertensive medication
therapy, nurses can encourage persons to reduce
their risk of hypertension through dietary
changes including a lower sodium intake (a
good guideline is less than one teaspoon per
day or under 2,000 mg for those with heart
failure), avoidance of excess alcohol and caffeine
consumption, and weight loss if obese. Increasing
regular exercise and avoiding smoking also
decrease the risk of hypertension. Nurses should
encourage persons to have their blood pressure
checked regularly and more frequently as they
get older.
Early diagnosis and treatment of prehypertension can help persons avoid the morbidities
and increased mortality associated with high
blood pressure. Rehabilitation nurses can educate
patients and the general public about the need
for treatment and the variety of medications
that are useful in managing hypertension.
Incorporating blood pressure management into
patient education about stroke risk reduction
is important in all settings. By controlling high
blood pressure early with lifestyle changes and
medications, people can positively affect their
own health and decrease the risk of stroke and
heart disease associated with this silent killer.
Kristen L. Mauk, PhD RN CRRN-A APRN BC,
is an associate professor of nursing at Valparaiso
University, Valparaiso, IN.
References
American Heart Association. (2005). Heart disease
and stroke statistics: 2005 update [Brochure].
Dallas: Author.
American Heart Association. (2006). Blood
pressure lowering drugs. Retrieved April 15, 2006,
from www.americanheart.org/presenter.
Jones, D. (2003). New high blood pressure
guidelines say start early, treat aggressively
[Journal report]. Retrieved April 15, 2005, from
www.americanheart.org/presenter.
Kennedy-Malone, L. K., Fletcher, K. R., & Plank,
L. M. (2000). Management Guidelines for
Gerontological Nurse Practitioners. Philadelphia:
F. A. Davis.
The Washington Manual: Geriatrics Subspecialty
Consult. (2005). Philadelphia: Lippincott,
Williams, & Wilkins.
Table 1.Commonly Prescribed Medications to Treat
Hypertension (American Heart Association, 2006)
Diuretics
Amiloride (Midamor)
Bumetanide (Bumex)
Chlorothiazide (Diuril)
Chlorthalidone (Hygroton)
Furosemide (Lasix)
Hydrochlorothiazide (Esidrix, Hydrodiuril)
Indapamide (Lozol)
Spironolactone (Aldactone)
Beta-Blockers
Acebutolol (Sectral)
Atenolol (Tenormin)
Betaxolol (Kerlone)
Bisoprolol/hydrochlorothiazide (Ziac)
Bisoprolol (Zebeta)
Carteolol (Cartrol)
Metoprolol (Lopressor, Toprol XL)
Nadolol (Corgard)
Propranolol (Inderal)
Sotalol (Betapace)
Timolol (Blocadren)
ACE Inhibitors
Benazepril (Lotensin)
Captopril (Capoten)
Enalapril (Vasotec)
Fosinopril (Monopril)
Lisinopril (Prinivil, Zestril)
Moexipril (Univasc)
Perindopril (Aceon)
Quinapril (Accupril)
Ramipril (Altace)
Trandolapril (Mavik)
AG-2 Receptor Agonists
Candesartan (Atacand)
Eprosartan (Teveten)
Irbesartan (Avapro)
Losartan (Cozaar)
Telmisartan (Micardis)
Valsartan (Diovan)
Calcium Channel Blockers
Amlodipine (Norvasc, Lotrel)
Bepridil (Vascor)
Diltiazem (Cardizem, Tiazac)
Felodipine (Plendil)
Nifedipine (Adalat, Procardia)
Nimodipine (Nimotop)
Nisoldipine (Sular)
Verapamil (Calan, Isoptin, Verelan)
Alpha-Blockers
Doxazosin mesylate (Cardura)
Prazosin hydrochloride (Minipress)
Prazosin and polythiazide (Minizide)
Terazosin hydrochloride (Hytrin)
Central Alpha Agonists
Clonidine hydrochloride (Catapres)
Clonidine hydrochloride and chlorthalidone
(Clorpres, Combipres)
Guanabenz Acetate (Wytensin)
Guanfacine hydrochloride (Tenex)
Methyldopa (Aldomet)
Methyldopa and chlorothiazide (Aldoclor)
Methyldopa and hydrochlorothiazide (Aldoril)