Pharmacotherapy of Hypertension
PST 06106
Basic Pharmacotherapy
Session 24: Pharmacotherapy of Hypertension
Learning Objective
By the end of this session students are expected to be able to:
Define hypertension
Explain pathophysiology of hypertension
Explain the clinical presentation of hypertension
Outline diagnosis of hypertension
Describe pharmacological treatment of hypertension
Describe the monitoring of hypertension therapy
Activity: Buzzing
What is
Hypertension
?
Definition of Hypertension
Hypertension is defined as a systolic blood pressure (SBP) of higher than 140mmHg or a diastolic blood pressure (DPB) higher than 90mmHg
The classification of BP is as been follows
:
Normal: Systolic lower than 120 mm Hg, diastolic lower than 80 mm Hg
Prehypertension: Systolic 120-139 mm Hg, diastolic 80-89 mm Hg
Stage 1: Systolic 140-159 mm Hg, diastolic 90-99 mm Hg
Stage 2: Systolic 160 mm
Hg or greater, diastolic 100 mm Hg or
greater
Definition of Hypertension
Cont.…..
Hypertension may be;
Primary, which may develop as a result of environmental or genetic causes, or
Secondary, which has multiple etiologies, including renal, vascular, and endocrine causes.
Primary or essential hypertension accounts for 90-95% of adult cases, and secondary hypertension accounts for 2-10% of cases.
Pathophysiology
of Hypertension
Multiple factors that control BP are potential contributing components in the development of essential hypertension.
These include;
Malfunctions in either humoral [i.e., the renin-angiotensin- aldosterone system (RAAS)] or vasodepressor mechanisms,
Abnormal neuronal mechanisms,
Defects in peripheral autoregulation, and
Disturbances in sodium, calcium, and natriuretic hormone.
Pathophysiology of Hypertension
Cont
…
Many of these factors are cumulatively affected by the multifaceted RAAS, which ultimately regulates arterial BP.
It is probable that no one factor is solely responsible for essential hypertension
.
Clinical
Presentation and Diagnosis of Hypertension
General:
The patient may appear healthy or may have the presence of additional CV risk factors:
Age (greater than or equal to 55 for men, greater than or equal to 65 for women)
Diabetes mellitus
Dyslipidemia
(elevated cholesterol or fats in the blood)
Microalbuminuria
Family history of premature CV disease
Physical inactivity
Tobacco
use
Clinical Presentation and Diagnosis of Hypertension
Cont
….
Symptoms:
Usually none related to elevated BP.
Signs:
Previous BP values in either the prehypertension or the hypertension category.
Laboratory Tests:
BUN/serum creatinine,
fasting lipid panel,
fasting blood glucose
,
Clinical Presentation and Diagnosis of Hypertension
Cont
….
Laboratory Tests….
serum
electrolytes (sodium, potassium),
Spot urine albumin-to-creatinine ratio.
The patient may have normal values and still have hypertension.
However, some may have abnormal values that are consistent with either additional CV risk factors or hypertension-related damage.
Other Diagnostic Tests:
12-lead electrocardiogram,
Estimated glomerular filtration rate [using modification of diet in renal disease (MDRD) equation].
Clinical Presentation and Diagnosis of Hypertension
Cont
….
Hypertension-Related
Target-Organ Damage:
The patient may have a previous medical history or diagnostic findings that indicate
the presence of hypertension-related target-organ damage:
Brain (stroke, transient ischemic attack, dementia)
Eyes (retinopathy)
Heart (left ventricular hypertrophy, angina, prior MI, prior coronary revascularization, heart failure)
Kidney (chronic kidney disease)
Peripheral vasculature (peripheral arterial disease)
Activity
: Small Group Discussion
What is the treatment of
Hypertension
?
Pharmacological Treatment Of Hypertension
The overall goal of treating hypertension is to reduce hypertension- associated morbidity and mortality.
. CV
events, cerebrovascular events, heart failure, and kidney disease).
Reducing CV risk remains the primary purpose of hypertension therapy and the specific choice of drug therapy is significantly influenced by evidence demonstrating such CV risk reduction.
Treating patients with hypertension to achieve a desired target BP value is simply a surrogate goal of therapy
Pharmacological Treatment Of
Hypertension
Cont
….
In most cases the target BP should be: systolic below 140 mmHg and diastolic below 90 mmHg.
In diabetic patients and patients with cardiac or renal impairment, target BP should be below 130/80mmHg;
The
choice of initial drug therapy depends on the degree of BP elevation and presence of compelling indications (
e.g
coexisting conditions such as diabetes and other cardiovascular conditions)
Most patients with stage 1 hypertension should be initially treated with a first-line antihypertensive drug, or the combination of two agents.
Combination drug therapy is recommended for patients with more severe BP elevation (stage 2 hypertension), using preferably two first-line antihypertensive drugs
.
Pharmacological Treatment Of Hypertension
Cont
….
Recommended Initial Medication Doses For Hypertension Treatment
Thiazide
diuretics
Hydrochlothiazide
12.5mg/daily
OR
Bendroflumethiazide
5mg/daily
OR
Indapamide
5mg/daily preferred for patient with previous stroke/TIA
Pharmacological Treatment Of Hypertension
Cont
….
Recommended Initial Medication Doses For Hypertension
Treatment…..
Loop
diuretics
Furosemide initial dose 40mg twice a day
OR
Torsemide
5mg/daily
Dose can be up scaled depending on congestive status to maximum dose
Pharmacological Treatment Of Hypertension
Cont
….
Recommended Initial Medication Doses For Hypertension
Treatment……
Mineralocorticoid
(Aldosterone) Receptor antagonist
Spironolactone 25mg/daily
OR
Eplerenone
25mg/daily
Angiotensin-Converting Enzyme Inhibitor (ACEI)
Captopril 6.125mg, 12.5mg or 25mg three times daily
OR
Enalapril
10mg twice a day
OR
Perindopril 8mg/daily orally
Pharmacological Treatment Of Hypertension
Cont
….
Angiotensin Receptor Blocker–ARB
(*Don’t combine with ACEI contraindications, indicated in patient sensitive to ACEIs)
Losartan 50mg/daily*
Beta–blocker
Atenolol 50mg/daily
OR
Metoprolol 50mg/daily
Pharmacological Treatment Of Hypertension
Cont
….
Calcium
Channel Blocker (
Dihydropyridines
):
Nifedipine
(Slow Release/Long Acting) 20mg/30mg/ 60mg/90mg/daily
OR
Amlodipine 5mg or 10mg/daily
Non–
dihydropyridine
Verapamil 30mg twice–three times a daily
OR
Diltiazem 30mg twice–three times a day
Monitoring of Hypertension Therapy
Routine ongoing monitoring to assess disease progression, the desired effects of antihypertensive
therapy
The
monitoring parameters include;
Signs
and symptoms of Disease Progression
Efficacy
of
antihypertensive
and BP goal attainment, and
Undesired
adverse side effects (toxicity)
Monitoring of Hypertension
Therapy
Cont
…
Disease Progression
Patients should be monitored for signs and symptoms of progressive hypertension-associated target-organ disease.
A careful history for ischemic chest pain (or pressure), palpitations, dizziness, dyspnea, orthopnea, headache, sudden change in vision, one-sided weakness, slurred speech, and loss of balance should be taken to assess the presence of CV and cerebrovascular hypertensive complications
Monitoring of Hypertension
Therapy
Cont
…
E
fficacy
The most important strategy to prevent CV morbidity and mortality in hypertension is BP control to goal values
Clinic-based BP monitoring remains the standard for managing hypertension.
BP response should be evaluated 2 to 4 weeks after initiating or making changes in therapy.
Once goal BP values are attained, assuming no signs or symptoms of acute target-organ
disease are present, BP monitoring can be done every 3 to 6 months.
More frequent evaluations are required for patients with a history of poor control, nonadherence, progressive target-organ damage, or symptoms of adverse drug effects.
Self-measurements of BP or automated ambulatory BP monitoring can be useful clinically to establish effective 24-hour
control
Monitoring of Hypertension
Therapy
Cont
…
Toxicity
Patients should be monitored routinely for symptoms of adverse drug reactions.
Laboratory monitoring should typically occur 2 to 4 weeks after starting a new agent or dose increase, and then every 6 to 12 months in stable patients.
Key
Points
Hypertension
is defined as a systolic blood pressure (SBP) of higher than 140mmHg or a diastolic blood pressure (DPB) higher than 90mmHg
The overall goal of treating hypertension is to reduce hypertension- associated morbidity and mortality.
This morbidity and mortality is related to hypertension-associated target-organ damage
The choice of initial drug therapy depends on the degree of BP elevation and presence of compelling indications (
e.g
coexisting conditions such as diabetes and other cardiovascular conditions)
Evaluation
What
is Hypertension?
What is the pathophysiology of
Hypertension?
What are the signs and symptoms of Hypertension?
How is the treatment of Hypertension?
References
Wells
BG,
DiPiro
J,
Schwinghammer
T (2013),
Pharmacotherapy Handbook
(6
th
Ed). New York, NY: McGraw-Hill.
DiPiro
JT, Talbert RL, Yee GC, Matzke GR, Wells BG, Posey ML, (2008):
Pharmacotherapy: A Pathophysiologic Approach
(7
th
ed
): New York, NY: McGraw-Hill.
Katz M D.,
Matthias KR.,
Chisholm-Burns M A.,
Pharmacotherapy(2011)
Principles & Practice Study Guide: A Case-Based Care Plan Approach
:
New York, NY: McGraw-Hill.
Schwinghammer
TL, Koehler JM (2009)
Pharmacotherapy Casebook: A Patient-Focused Approach
(7
th
ed
): New York, NY: McGraw-Hill.
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