Blood Pressure
Blood pressure = CO × SVR CO = cardiac output SVR = systemic vascular resistance
Hypertension = high blood pressure
Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 2
Four stages, based on BP measurements
1. Normal
2. Prehypertension
3. Stage 1 hypertension
4. Stage 2 hypertension
*New guidelines pending
Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and
Treatment of High Blood Pressure (JNC-7)*
Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 4
Hypertension can also be defined by its cause Unknown cause
Essential, idiopathic, or primary hypertension 90% of cases
Known cause Secondary hypertension 10% of cases
Classification of BP
Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 5
Classroom Response Question
The number of people with hypertension in the United States is estimated to be:
A.10 million.
B.50 million.
C.75 million.
D.100 million.
Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 6
Parasympathetic nervous system Stimulates smooth muscle, cardiac muscle, glands
Sympathetic nervous system Stimulates the heart, blood vessels, skeletal muscle
Autonomic Nervous System
Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 7
Location of the Nicotinic Receptors in the PNS and SNS
Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 8
Medications used to treat hypertension Categories
Adrenergic drugs Angiotensin-converting enzyme (ACE) inhibitors Angiotensin II receptor blockers (ARBs) Calcium channel blockers (CCBs) Diuretics Vasodilators Direct renin inhibitors
Antihypertensive Drugs
Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 9
Centrally and peripherally acting adrenergic neuron blockers
Centrally acting alpha2 receptor agonists
Peripherally acting alpha1 receptor blockers
Adrenergic Drugs: Five Subcategories
Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 11
Peripherally acting beta receptor blockers (beta blockers) Cardioselective (beta1 receptors)
Nonselective (both beta1 and beta2 receptors)
Peripherally acting dual alpha1 and beta receptor blockers
Adrenergic Drugs: Five Subcategories (cont’d)
Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 12
Centrally acting alpha2 receptor agonists Stimulate alpha2-adrenergic receptors in the brain
Decrease sympathetic outflow from the CNS Decrease norepinephrine production Stimulate alpha2-adrenergic receptors, thus reducing
renin activity in the kidneys Result in decreased blood pressure
Adrenergic Drugs
Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 13
Centrally acting alpha2 receptor agonists (cont’d) clonidine (Catapres) methyldopa (Aldomet)
• Can be used for hypertension in pregnancy
Adrenergic Drugs (cont’d)
Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 14
Peripheral alpha1 blockers/antagonists Block alpha1-adrenergic receptors
doxazosin (Cardura) terazosin (Hytrin) prazosin (Minipress)
Adrenergic Drugs (cont’d)
Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 15
Beta blockers Reduce BP by reducing heart rate through beta1
blockade Cause reduced secretion of renin Long-term use causes reduced peripheral vascular
resistance Examples: nebivolol (Bystolic), propranolol (Inderal),
atenolol (Tenormin), others
Adrenergic Drugs (cont’d)
Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 16
Dual-action alpha1 and beta receptor blockers Reduce heart rate (beta1 receptor blockade)
Cause vasodilation (alpha1 receptor blockade)
carvedilol (Coreg) and labetalol Result in decreased blood pressure
Adrenergic Drugs (cont’d)
Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 17
All used to treat hypertension Centrally acting alpha2 receptor agonists
Treatment of hypertension, either alone or with other drugs
Usually used after other drugs have failed because of adverse effects
Clonidine is useful in the management of withdrawal symptoms in opioid-dependent persons
Adrenergic Drugs: Indications
Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 18
Peripherally acting alpha1 receptor agonists Treatment of hypertension Some used to relieve symptoms of BPH
• tamsulosin (Flomax)
Management of severe heart failure (HF) when used with cardiac glycosides and diuretics
Adrenergic Drugs: Indications (cont’d)
Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 19
High incidence of orthostatic hypotension Most common
Bradycardia with reflex tachycardia Dry mouth Drowsiness, sedation Constipation Depression Edema Sexual dysfunction
Adrenergic Drugs: Adverse Effects
Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 20
Adrenergic Drugs: Adverse Effects (cont’d)
Other Headaches Sleep disturbances Nausea Rash Cardiac disturbances (palpitations), others
Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 21
Classroom Response Question
When administering an alpha-adrenergic drug for hypertension, it is most important for the nurse to assess the patient for the development of:
A.hypotension.
B.hyperkalemia.
C.oliguria.
D.respiratory distress.
Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 22
Large group of safe and effective drugs Often used as first-line drugs for HF
and hypertension May be combined with a thiazide diuretic or
calcium channel blocker
Angiotensin-Converting Enzyme (ACE) Inhibitors
Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 23
captopril (Capoten) benazepril (Lotensin) enalapril (Vasotec) fosinopril (Monopril) lisinopril (Prinivil) moexipril (Univasc) quinapril (Accupril) Others
ACE Inhibitors (cont’d)
Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 24
Inhibit angiotensin-converting enzyme, which is responsible for converting angiotensin I (through the action of renin) to angiotensin II
Angiotensin II is a potent vasoconstrictor and causes aldosterone secretion from the adrenal glands
ACE Inhibitors:Mechanism of Action
Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 25
Block angiotensin-converting enzyme, thus preventing the formation of angiotensin II
Prevent the breakdown of the vasodilating substance bradykinin
Result in decreased systemic vascular resistance (afterload), vasodilation, and therefore decreased blood pressure
ACE Inhibitors:Mechanism of Action (cont’d)
Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 26
Hypertension HF (either alone or in combination with diuretics
or other drugs) Slow progression of left ventricular hypertrophy
after MI (cardioprotective) Renal protective effects in patients with diabetes
ACE Inhibitors:Indications
Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 27
Classroom Response Question
A patient with type II diabetes has a new prescription for the angiotensin-converting enzyme (ACE) inhibitor lisinopril. She questions this order because her physician has never told her that she has hypertension. What is the best explanation for this order? A. The doctor knows best.
B. The patient is confused.
C. This medication has cardioprotective properties.
D. This medication has a protective effect on the kidneys for patients with type II diabetes.
Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 28
Drugs of choice in hypertensive patients with HF Drugs of choice for diabetic patients
ACE Inhibitors: Indications (cont’d)
Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 29
Classroom Response Question
A patient with a history of pancreatitis and cirrhosis is also being treated for hypertension. Which drug will most likely be ordered for this patient?
A.clonidine
B.prazosin
C.diltiazem
D.captopril
Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 30
Captopril and lisinopril are NOT prodrugs Prodrugs are inactive in their administered form and
must be metabolized in the liver to an active form so as to be effective
Captopril and lisinopril can be used if a patient has liver dysfunction, unlike other ACE inhibitors that are prodrugs
ACE Inhibitors (cont’d)
Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 31
Fatigue Dizziness Headache Mood changes Impaired taste Possible hyperkalemia Dry, nonproductive cough, which reverses when
therapy is stopped Angioedema: rare but potentially fatalNote: First-dose hypotensive effect may occur
ACE Inhibitors: Adverse Effects
Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 32
Also referred to as angiotensin II blockers or ARBs
Well tolerated Do not cause a dry cough
Angiotensin II Receptor Blockers
Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 33
losartan (Cozaar) eprosartan (Teveten) valsartan (Diovan) irbesartan (Avapro) candesartan (Atacand) olmesartan (Benicar) telmisartan (Micardis) azilsartan (Edarbi)
Angiotensin II Receptor Blockers
Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 34
Allow angiotensin I to be converted to angiotensin II, but block the receptors that receive angiotensin II
Block vasoconstriction and release of aldosterone
Angiotensin II Receptor Blockers: Mechanism of Action
Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 35
Hypertension Adjunctive drugs for the treatment of HF May be used alone or with other drugs such as
diuretics
Angiotensin II Receptor Blockers: Indications
Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 36
Upper respiratory infections Headache May cause occasional dizziness, inability to
sleep, diarrhea, dyspnea, heartburn, nasal congestion, back pain, fatigue
Hyperkalemia much less likely to occur
Angiotensin II Receptor Blockers: Adverse Effects
Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 37
Classroom Response Question
Which statement about angiotensin II receptor blockers does the nurse identify as being true?
A.Hyperkalemia is more likely to occur than when using ACE inhibitors.
B.Cough is more likely to occur than when using ACE inhibitors.
C.Upper respiratory infection is a common adverse effect.
D.Overdose is usually manifested by hypertension and bradycardia.
Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 38
Cause smooth muscle relaxation by blocking the binding of calcium to its receptors, preventing muscle contraction
Results in: Decreased peripheral smooth muscle tone Decreased systemic vascular resistance Decreased blood pressure
Calcium Channel Blockers:Mechanism of Action
Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 39
Angina Hypertension Dysrhythmias Migraine headaches Raynaud’s disease
Calcium Channel Blockers: Indications
Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 40
Decrease plasma and extracellular fluid volumes Results
Decreased preload Decreased cardiac output Decreased total peripheral resistance
Overall effect Decreased workload of the heart and decreased
blood pressure
Diuretics
Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 41
Thiazide diuretics are the most commonly used diuretics for hypertension
Listed as first-line antihypertensives in the JNC-7 guidelines
Diuretics (cont’d)
Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 42
diazoxide (Hyperstat) hydralazine HCl (Apresoline) minoxidil (Loniten) sodium nitroprusside (Nipride, Nitropress)
Vasodilators
Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 43
Directly relax arteriolar and/or venous smooth muscle
Results in: Decreased systemic vascular response Decreased afterload Peripheral vasodilation
Vasodilators:Mechanism of Action
Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 44
Treatment of hypertension May be used in combination with other drugs Sodium nitroprusside and intravenous diazoxide
are reserved for the management of hypertensive emergencies
Vasodilators: Indications
Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 45
Before beginning therapy, obtain a thorough health history and head-to-toe physical examination
Assess for contraindications to specific antihypertensive drugs
Assess for conditions that require cautious use of these drugs
Nursing Implications
Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 46
Educate patients about the importance of not missing a dose and taking the medications exactly as prescribed
Instruct patients to check with their physician for instructions on what to do if a dose is missed; patients should never double up on doses if a dose is missed
Monitor BP during therapy; instruct patients to keep a journal of regular BP checks
Nursing Implications (cont’d)
Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 47
Instruct patients that these drugs should not be stopped abruptly because this may cause a rebound hypertensive crisis, and perhaps lead to stroke
Oral forms should be given with meals so that absorption is more gradual and effective
Administer IV forms with extreme caution, and use an IV pump
Nursing Implications (cont’d)
Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 48
Remind patients that medication is only part of therapy. Encourage patients to watch their diet, stress level, weight, and alcohol intake
Instruct patients to avoid smoking and eating foods high in sodium
Encourage supervised exercise
Nursing Implications (cont’d)
Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 49
Teach patients to change positions slowly to avoid syncope from postural hypotension
Instruct patients to report unusual shortness of breath; difficulty breathing; swelling of the feet, ankles, face, or around the eyes; weight gain or loss; chest pain; palpitations; or excessive fatigue
Nursing Implications (cont’d)
Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 50
Male patients who take these drugs may not be aware that impotence is an expected effect, and this may influence compliance with drug therapy
If patients are experiencing serious adverse effects, or if they believe the dose or medication needs to be changed, they should contact their physician immediately
Nursing Implications (cont’d)
Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 51
Hot tubs, showers, or baths; hot weather; prolonged sitting or standing; physical exercise; and alcohol ingestion may aggravate low blood pressure, leading to fainting and injury; patients should sit or lie down until symptoms subside
Patients should not take any other medications, including over-the-counter drugs, without first getting the approval of their physician
Nursing Implications (cont’d)
Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 52
Educate patients about lifestyle changes that may be needed Weight loss Stress management Supervised exercise Dietary measures
Nursing Implications (cont’d)
Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 53