Download Cardiovascular Drugs

Cardiovascular Drugs
• As blood is pumped through the arteries, it
creates pressure within the wall of the arteries
• As the heart contracts, this increased pressure
is called the systolic pressure
• As the heart relaxes and fills, this decreased
pressure is called the diastolic pressure
Blood Pressure
• Blood pressure is written as a fraction of
systolic over diastolic pressure in
mmHg(mercury)
• Normal is 120/80 mmHg
Blood Pressure
• Blood pressure is VITAL to life
• A blood pressure of zero is a sign of death
• Blood pressure is a VITAL sign
Let’s take a blood pressure
Hypertension
• Is High Blood Pressure
• HTN
Hypertension
• Is measured by consistent elevation in blood
pressure, either
• Systolic ≥ 140mmHg
• Diastolic ≥90mmHg
Hypertension
• Long standing, uncontrolled HTN damages
blood vessels resulting in many types of organ
damage
Essential Hypertension
• Essential HTN is the most common form of
HTN
• Cause of essential HTN is unknown
Essential Hypertension has many risk
factors:
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Family history of HTN
Sex
Race
Salt
Stress
Obesity, lack of exercise
Smoking
Secondary HTN
• Unlike essential HTN, secondary HTN has a
specific cause for the elevated blood pressure
Secondary HTN
• Kidney Disease
• Pheochromocytoma – a type of tumor that
makes too much epinephrine or too much
catecholamines
• Cushing’s Disease
• Pregnancy
• Vascular Anomalies
• Neurologic Disease
Symptoms of HTN
• HTN usually has NO symptoms
• It is usually detected on a routine visit to a
medical clinic
• HTN usually has NO symptoms
• This is why it is so difficult to convince people
to take medication for HTN
Symptoms of HTN
• HTN can cause many symptoms
• Headache and visual changes, especially
during stress are common early symptoms
Symptoms of HTN
• When HTN is severe enough to cause acute
visual, neurologic, or any other organ damage
this is called MALIGNANT HYPERTENSION
HTN damages blood vessels
• Long term sustained hypertension damages
blood vessels
• Blood vessels exposed to high blood pressures
become thickened and hardened, making
them less flexible
Arteriosclerosis
• Blood vessels exposed to high blood pressures
become thickened and hardened, making
them less flexible
HTN damages blood vessels
• Fatty deposits can form on the arteries call
plaques, which cause the artery to narrow and
become blocked
• This is called Atherosclerosis
Know the difference between:
• Arteriosclerosis
• Atherosclerosis
Infarction
• When narrow arteries become blocked and
blood supply to an organ is stopped, organ
damage results
• This damage is called infarction
HTN causes brain damage
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HTN is a major cause of stroke
- brain attack
- cerebrovascular accident (CVA)
- cerebral infarction
- apoplexy
HTN causes brain damage
Aneurysm
• With high blood pressure, a weakening of the
arterial wall may balloon out (aneurysm) and
burst causing hemorrhage (bleeding) and even
death
Aneurysm
Aneurysm
• Although aneurysm can occur on any artery,
the two most common places for aneurysm
are:
- Brain – cerebrovascular aneurysm
- Aorta – abdominal aortic aneurysm
HTN damages the eyes
• Because HTN damages blood vessels, HTN
damages the blood supply to the eyes, and
can lead to blindness
Normal Retina
HTN damages the kidneys
• Because HTN damages the blood vessels, HTN
damages the kidneys, this is called
nephrosclerosis, and can lead to kidney failure
Nephron
HTN damages the heart
• Because HTN damages the blood vessels, HTN
damages the heart by infarction, hypertrophy
or cardiomyopathy
Myocardial Infarction
Ventricular Hypertrophy
Dilated Cardiomyopathy
The kidneys help regulate blood
pressure
• The kidneys play an important role in the longterm regulation of blood pressure
Immediate Control
• Parasympathetic Nervous System
• Sympathetic Nervous System/Adrenergic NS
Long Term Control
• Kidneys
Kidneys and Blood Pressure
• Kidneys help regulate the balance of salt and
water in the body
• Kidneys excrete water soluble waste
substances, salt and water
Kidneys are Filters
• The kidneys contain millions of microscopic
filtering units, called nephrons which are the
working components of the kidnyes
Kidneys are Filters
• Many substances cannot pass through the
filter and remain in the blood
• Many substances pass through the filters (like
glucose) but are reabsorbed back into the
blood
Kidneys are Filters
• Many substances pass through the filters and
are excreted into the urine
Kidneys regulate blood volume
• When blood volume decreases, kidneys will
retain salt and water
• When blood volume increases, kidneys will
excrete salt and water
Renal Hormones and Volume Control
• Blood volume is monitored by the kidneys and
continually adjust water and salt levels to help
maintain consistent blood pressure
Renal Hormones and Volume Control
• The blood vessels supplying the nephrons
contain special cells that detect blood
pressure
Renal Hormones and Volume Control
• If blood pressure falls below a set point, a
renal hormone called Renin is secreted into
the blood stream
Renin and Volume Control
• Renin converts angiotensin to angiotensin 1,
which is converted to angiotensin 2 by the
lungs
• Angiotensin 2 causes vasoconstriction which
increases blood pressure
• Angiotensin 2 also stimulates the adrenal
cortex to produce aldosterone
Aldosterone and Volume Control
• Aldosterone acts on the kidneys to keep salt
and water in the blood, resulting in increased
blood volume
• Medulla – inside
- epinephrine (adrenaline)
Cortex – outside
- aldosterone (mineralocorticoid)
- hydrocortisone (glucocorticoid)
Antidiuretic Hormone (ADH) and
Volume Control
• Antidiuretic Hormone (ADH) is also called
Vasopressin, secreted by the brain in response
to low blood pressure, acts on the kidneys to
retain water, resulting in increased blood
volume
Drugs for HTN
• Adrenergic Antagonists
• - β-blockers
• - “Beta Blockers”
– Propanolol
– Atenolol
Adrenergic Antagonists
• - α-blockers
• - alpha-blockers
– Doxazosin
Drugs for HTN
• Central α-agonist
• - clonidine
• Clonidine stimulates alpha adrenoreceptors in
the brain stem. This action results in reduced
sympathetic outflow from the central nervous
system and in decreased in peripheral
resistance, renal vascular resistance, heart
rate and blood pressure
Drugs for HTN
• Thiazide diuretic
– Hydrochlorothiazide (HCTZ)
Drugs for HTN
• Angiotensin Converting Enzyme Inhibitors
• ACE
– Captopril
Drugs for HTN
• Angiotensin II receptor blockers
• - losartan
Drugs for HTN
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Calcium Channel Blockers
- dilates arterioles
- relaxes smooth muscle
- come in 3 classes
Drugs for HTN
• Calcium channel blockers
• - nifedipine is a dihydropyridine CCB
Drugs for HTN
• Calcium Channel Blocker
• - Verapamil is a phenylalkylamine ccb
Drugs for HTN
• Calcium Channel Blocker
• - Diltiazem is a benzothiazepine ccb