Transcript Chapter 16 Cholinesterase Inhibitors

Chapter 47
Drugs for Hypertension
Copyright © 2013, 2010 by Saunders, an imprint of Elsevier Inc.
Classification of Blood Pressure (BP)
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Four BP categories (defined by JNC 7):
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Normal
• Systolic BP below 120 mm Hg and diastolic BP below
80 mm Hg
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Prehypertension
• Systolic BP 120–139 mm Hg or diastolic BP 80–89 mm
Hg
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Hypertension
• Systolic BP above 140 mm Hg or diastolic BP above
90 mm Hg
• Stage 2 hypertension: systolic BP and diastolic BP in
different categories (eg, 160/92 mm Hg)
Copyright © 2013, 2010 by Saunders, an imprint of Elsevier Inc.
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Types of Hypertension
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Two broad categories of hypertension
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Primary (essential) hypertension
• No identifiable cause
• Chronic, progressive disorder
• Population: older adults, African Americans, Mexican
Americans, postmenopausal women
• Treated but not cured (lifelong condition)
• Referred to as “essential hypertension”
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Secondary hypertension
• Identifiable primary cause
• Possible to treat the cause directly
• Some individuals can actually be cured
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Consequences of Hypertension
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Heart disease
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Myocardial infarction (MI)
Heart failure
Angina pectoris
Kidney disease
Stroke
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Basic Considerations
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Benefits of lowering blood pressure
Patient evaluation
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Hypertension with a treatable cause
Factors that increase cardiovascular risk
Diagnostic tests
Treatment goals
Therapeutic interventions
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Lifestyle Modifications
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Sodium restriction
DASH (Dietary Approaches to Stop
Hypertension) eating plan
Alcohol restriction
Aerobic exercise
Smoking cessation
Maintenance of potassium and calcium intake
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Pharmacologic Therapy
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Review of blood pressure control
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Principal determinants of blood pressure
• Arterial pressure = Cardiac output × Peripheral
resistance
• Cardiac output
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Heart rate
Myocardial contractility
Blood volume
Venous return
Systems that help regulate blood pressure
• Sympathetic baroreceptor reflex
• Renin-angiotensin-aldosterone system
• Renal regulation of blood pressure
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Pharmacologic Therapy
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Antihypertensive mechanisms: sites of drug action
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Brainstem
Sympathetic ganglia
Terminals of adrenergic nerves
Beta1-adrenergic receptors on the heart
Alpha1-adrenergic receptors on blood vessels
Vascular smooth muscle
Renal tubules
Beta1 receptors on juxtaglomerular cells
Angiotensin-converting enzyme
Angiotensin II receptors
Aldosterone receptors
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Pharmacologic Therapy
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Classes of antihypertensive drugs
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Diuretics
• Thiazide diuretics
• High-ceiling (loop) diuretics
• Potassium-sparing diuretics
 Sympatholytics (antiadrenergic drugs)
• Beta-adrenergic blockers
• Alpha1 blockers
• Alpha/beta blockers: carvedilol and labetalol
• Centrally acting alpha1 agonists
• Adrenergic neuron blockers
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Pharmacologic Therapy
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Sympatholytics (antiadrenergic drugs)
(cont’d)
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Direct-acting vasodilators: hydralazine and
minoxidil
Calcium channel blockers
Drugs that suppress RAAS
• ACE inhibitors
• Angiotensin II receptor blockers
• Aldosterone antagonists
• Direct renin inhibitors
ACE = angiotensin-converting enzyme; RAAS = renin-angiotensin-aldosterone system.
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Pharmacologic Therapy
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Fundamentals of hypertension drug therapy
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Treatment algorithm
Initial drug selection
• Patients WITHOUT compelling indications
• Patients WITH compelling indications
 Adding drugs to the regimen
• Rationale for drug selection
• Benefits of multidrug therapy
 Dosing
 Step-down therapy
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Pharmacologic Therapy
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Individualizing therapy
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Patients with comorbid conditions
• Renal disease
• Diabetes
Patients in special populations
• African Americans
• Children and adolescents
• The elderly
Copyright © 2013, 2010 by Saunders, an imprint of Elsevier Inc.
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Pharmacologic Therapy
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Minimizing adverse effects
Promoting adherence
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Why adherence can be difficult to achieve
Ways to promote adherence
• Educate the patient
• Teach self-monitoring
• Minimize side effects
• Establish a collaborative relationship
• Simplify the regimen
• Other measures
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Drugs for Hypertensive Emergencies
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Sodium nitroprusside
Fenoldopam
Labetalol
Diazoxide
Clevidipine
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Drugs for Hypertensive Disorders
of Pregnancy
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Chronic hypertension and pregnancy
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ACE inhibitors, ARBs, and DRIs are
contraindicated during pregnancy
Most other antihypertensives can be continued
during pregnancy
Preeclampsia and eclampsia
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Hydralazine
Magnesium sulfate (anticonvulsant)
ARB = angiotensin receptor blocker; DRI = direct renin inhibitor.
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