Transcript Blood pressure

Antihypertensive
drugs
Dr. M. Kheir Mulki
What is the
Blood Pressure
?
• Blood pressure (BP) is the pressure exerted
by circulating blood upon the walls of blood
vessels.
• Blood pressure (BP) is one of the principal
vital signs.
BP = CO x PR
BP = blood pressure
CO = cardiac output
PR = peripheral resistance
• Cardiac output is the volume of blood
pumped by the heart per minute (mL
blood/min).
• Cardiac output is a function of heart rate
and stroke volume.
Under conditions of rest:
the parasympathetic fibers release
acetylcholine, which acts to slow the
pacemaker potential of
the SA node and thus
reduce heart rate.
Under conditions of physical or
emotional activity :
1. Sympathetic nerve fibers
release norepinephrine
2.The adrenal medulla
release epinephrine,
which acts to speed up the
pacemaker potential
of the SA node thus
increasing heart rate.
• An average person has a resting heart rate
of 70 beats/minute and a resting stroke
volume of 70 mL/beat.
• The cardiac output for this person at rest
is:
Cardiac Output = 70 (beats/min) X 70 (mL/beat) =
4900 mL/minute.
• The total volume of blood in the circulatory
system of an average person is about
5 liters (5000 mL).
• According to our calculations, the entire
volume of blood within the circulatory
sytem is pumped by the heart each minute
(at rest).
• During vigorous exercise, the cardiac
output can increase up to 7 fold (35
liters/minute).
What is the
Essential hypertension
?
Essential hypertension (also called primary or
idiopathic hypertension) is the form of
hypertension that by definition, has no
identifiable cause.
It is the most common type of hypertension,
affecting 95% of hypertensive patients
What is secondary
hypertension
?
• Secondary hypertension (inessential
hypertension) is a type of hypertension
which by definition is caused by an
identifiable underlying secondary cause.
• It is much less common(affecting only 5%
of hypertensive patients).
• It has many different causes including :
• Disorders of the adrenal gland (Cushing's
syndrome ,hyperaldosteronism and
pheochromocytoma)
• Kidney disease (polycystic kidney disease,
kidney tumor, kidney failure, narrow or blocked
main artery supplying the kidney)
• Drugs : (corticosteroids, NSAID ,weight loss
drugs , decongestants, birth control pills (the
estrogen component), and migraine
medications)
• Sleep apnea
• Thyroid and parathyroid problems
What is the classification of
Blood pressure
?
Isolated systolic hypertension: increased systolic
blood pressure at normal or decreased diastolic BP
Pseudohypertension : rigid arteries in old age.
White coat hypertension : induced by stress at
physical examination.
Masked hypertension : false finding of normal
blood pressure during the examination; opposite of
white coat hypertension.
What are the symptoms
of hypertension
?
• Often, patients diagnosed with essential
hypertension have no symptoms.
• Sometimes patients will experience a :
•Mild headache
•Tiredness
•Shortness of breath
•Confusion
•Dizziness
•Anxiety
•Visual changes
•Nausea and vomiting
•Perspiration
•Nose bleeds
•Pale or red skin
•An angina-like pain in the
chest
•Rarely, the first symptom may be a stroke
What is the physiological
mechanisms to maintain
normal blood pressure
?
1. Autonomic nervous system
responses.
2. Hormonal responses
The autonomic nervous system is the most
rapidly responding regulator of blood
pressure and receives continuous
information from the baroreceptors
situated in the carotid sinus and the aortic
arch.
This information is relayed to the brainstem
to the vasomotor centre (VMC).
Hormonal mechanisms
Hormonal mechanisms exist both for lowering
and raising blood pressure.
They act in various ways including
vasoconstriction, vasodilatation and alteration
of blood volume.
The principal hormones raising blood pressure
are:
1. Adrenaline and noradrenaline secreted
from the adrenal medulla in response to
sympathetic nervous system stimulation.
They increase cardiac output and cause
vasoconstriction and act very rapidly.
2. Renin- Angiotensin- Aldosterone axis :
Renin production is increased in the kidney
when stimulated by hypotension .
Angiotensin is converted in the lung to
Angiotensin II, which is a potent
vasoconstrictor.
In addition these hormones stimulate the
production of aldosterone from the
adrenal cortex which decreases urinary
fluid and electrolyte loss from the body.
Why Hypertension should be
Treated ?
To decrease:
• Cerebrovascular Accidents
35-40%
• Coronary events
20-25%
• Heart failure
50%
• Progression of renal disease
• Progression to severe hypertension
Therefore decreasing mortality rate
City Pharma Medical supprt
dept.
Lifestyle Modification
Modification
Weight reduction
Approximate SBP reduction
(range)
5–20 mmHg/10 kg weight loss
Adopt DASH eating plan
8–14 mmHg
Dietary sodium reduction
2–8 mmHg
Physical activity
4–9 mmHg
Moderation of alcohol
consumption
2–4 mmHg
Dietary Approaches to Stop Hypertension (DASH)
What can the patient
do?
 -Change lifestyle
 -Stop smoking
 -Lose weight
 -Exercise regularly
 -Cut down on alcohol
 -Eat a varied diet
 -Reduce stress by trying
different relaxation
techniques, or by avoiding
stressful situations.
Only 53%
Only 24%
of hypertensive patients are
being treated,
have their hypertension
under control.
Antihypertensive agents
Anti hypertensive agents
1.
2.
3.
4.
5.
6.
7.
ACE inhibitor
ARBS
Beta blockers
Calcium channel blockers
Central agents
Diuretics
vasodilators
Peter S. Sever, and Franz H. Messerli Eur Heart J
2011;eurheartj.ehr177
Published on behalf of the European Society of Cardiology. All rights reserved. © The
Author 2011. For permissions please email: [email protected]
Diuretics
• Diuretics ( water pills ) treat a variety of
conditions, such as :
• High blood pressure.
• Glaucoma.
• Edema.
• Heart failure.
• Kidney and liver problems
• and sometimes in weight loss.
The most common types of diuretic are:
• Thiazides (eg hydrochlorthiazide)
• Loop diuretics (eg furosemide)
• Potassium-sparing diuretics (eg
spirenolacton)
• Others : carboanhydrase inhibitors
(acetazolamid)
Vasodilators
• Vasodilator drugs relax the smooth muscle
in blood vessels, which causes the vessels
to dilate.
• Dilation of arterial (resistance) vessels
leads to a reduction in systemic vascular
resistance, which leads to a fall in arterial
blood pressure.
• Examples of vasodilators are Hydralazine and
Minoxidil .
• The vasodilator Hydralazine also may be used
to control high blood pressure in pregnant
women or to bring down extremely high blood
pressure in emergency situations.
• A liquid form of Minoxidil, used to promote
hair growth in people with certain kinds of
baldness and is applied directly to the scalp, is
sold without a prescription.
Beta blockers
Beta blockers block the action of endogenous
catecholamines (epinephrine (adrenaline)
and norepinephrine (noradrenaline) in
particular), on β-adrenergic receptors, part of
the sympathetic nervous system .
Beta-blockers are often prescribed for these
heart conditions:
• Compensated congestive heart failure
• High blood pressure
• Angina
• Abnormal heart rhythms
• Heart attack( post myocardial infarction )
• In addition, beta-blockers are sometimes
prescribed for glaucoma, migraine
headaches, and hyperthyroidism.
• Some beta-blockers are selective, which
means that they block beta 1 receptors
more than they block beta 2 receptors.
• Nonselective beta-blockers block both
beta 1 and beta 2 receptors.
Non-selective agents
Oxprenolol
• Penbutolol
• Pindolol
• Propranolol
• Sotalol
• Timolol
•
•
•
•
•
•
Alprenolol
Carteolol
Levobunolol
Mepindolol
Metipranolol
Nadolol
β1-Selective agents
•
•
•
•
•
Atenolol
Acebutolol
Betaxolol
Bisoprolol[1]
Esmolol
•
•
•
•
•
Metoprolol
Nebivolol
Amosulalol
Landiolol
Tilisolol
Angiotensin Converting
Enzyme Inhibitors
ACEi
ACE inhibitors can be divided into three
based on their molecular :groups
structure
• Sulfhydryl-containing agents
Captopril
Zofenopril
• Dicarboxylate-containing agents
Enalapril
Ramipril
Quinapril
Perindopril
Lisinopril
Benazepril
• Phosphonate-containing agents
Fosinopril
Angiotensin receptor blockers
(ARBs)
• ARBs prevent angiotensin II from binding
to the angiotensin II receptor on blood
vessels and other tissues.
Calcium channel blockers
1. Dihydropyridines : (high vascular selectivity)
Amlodipine – Nicardipine - Nifedipine .
Non-Dihydropyridines :
2. Verapamil (phenylalkylamine class): selective
for the myocardium.
3 . Diltiazem (benzothiazepine class):
intermediate between Verapamil and
Dihydropyridines.
JNC 8 (2014 Hypertension Guideline Management Algorithm)
1
JAMA. 2013;():. doi:10.1001/jama.2013.284427
2014 Hypertension Guideline Management Algorithm SBP indicates systolic blood pressure; DBP, diastolic blood
pressure; ACEI, angiotensin-converting enzyme; ARB, angiotensin receptor blocker; and CCB, calcium channel
blocker.aACEIs and ARBs should not be used in combination.bIf blood pressure fails to be maintained at goal, reenter the
algorithm where appropriate based on the current individual therapeutic plan.
JNC 8 (2014 Hypertension Guideline Management Algorithm)
2
JAMA. 2013;():. doi:10.1001/jama.2013.284427
2014 Hypertension Guideline Management Algorithm SBP indicates systolic blood pressure; DBP, diastolic blood
pressure; ACEI, angiotensin-converting enzyme; ARB, angiotensin receptor blocker; and CCB, calcium channel
blocker.aACEIs and ARBs should not be used in combination.bIf blood pressure fails to be maintained at goal, reenter the
algorithm where appropriate based on the current individual therapeutic plan.
JNC 8 (2014 Hypertension Guideline Management Algorithm)
3
JAMA. 2013;():. doi:10.1001/jama.2013.284427
2014 Hypertension Guideline Management Algorithm SBP indicates systolic blood pressure; DBP, diastolic blood
pressure; ACEI, angiotensin-converting enzyme; ARB, angiotensin receptor blocker; and CCB, calcium channel
blocker.aACEIs and ARBs should not be used in combination.bIf blood pressure fails to be maintained at goal, reenter the
algorithm where appropriate based on the current individual therapeutic plan.
Questions
Thank you