Diuretics Flashcards
Facts on Hypertension:
● Hypertension is a very common problem especially here in the Philippines.
● Worldwide, approximately 1 in 3 adults have high blood pressure.
● Initially, we do not give out medications
for hypertensive patients especially in the early stage.
● You can do other steps to prevent high blood pressure.
○ Give them healthy diet
○ Increase the physical activity
○ Avoid tobacco/smoking
○ Avoid harmful use of alcohol. Drink in small amounts only.
○ Manage stress in a healthy way
The most common cardiovascular disease occurs in 50% between what ages?
60-69 y.o.
There are also rising cases of younger patients having hypertension in terms of sex:
○ Especially in males.
○ Females are protected from cardiovascular disease if they are still menstruating.
○ But after menstruation or menopause the cardiovascular risk for women will equal to that of men.
What is the principal cause of stroke, CAD, MI, sudden cardiac death, heart failure, renal insufficiency and dissecting aortic aneurysm?
HPN
What is the major consideration in treatment and requires lifelong treatment?
Quality of life
Some can treat hypertension with serious lifestyle modification.
However, most individuals have a treatment for a lifetime.
You diagnose these individuals and give medications with emphasis on compliance and maintenance lifelong.
What increases the pathologic changes in blood vessels, especially arteries, and heart
which results to target organ damage (TOD)?
Sustained hypertension
What is usually asymptomatic until there is
already target organ damage (TOD)?
Hypertension
Diagnosis of Hypertension is based on reported BP readings:
○ At least 2 BP readings on 2 separate occasions.
○ Sustained increase in BP ≥140/90 mmHg.
BP =
CO + PVR
by inotropy/chronotropy +
increase venous return
Increased cardiac output
What is determined by arterial smooth muscle?
○ May be caused by plaques or blocks caused by atherosclerosis.
Increased PVR
What is due to circulating blood volume/kidney control?
Increased venous return
Initial hemodynamic alteration in HPN:
↑CO + Normal PVR
Causes of hypertension
Table on page 1
Genetic influences in hypertension:
● Genetic is a very big factor in hypertension.
○ We always ask our patient if they have any family disorders of hypertension or diabetes.
○ These 2 have genetic influence for the development of hypertension.
● Genetic defects such as:
○ Defects in renal sodium hemostasis
○ Functional vasoconstriction
○ Defects in vascular smooth muscle growth and structure
● These will all lead to the pathologic changes and findings seen in patients with hypertension.
● Defects in Renal Sodium hemostasis
lead to inadequate sodium excretion, which will cause salt and water retention, increasing the plasma and ECF volume thus increasing the cardiac output (autoregulation) resulting in hypertension.
● Functional vasoconstriction and defects in smooth muscle growth and structure, will increase the peripheral vascular resistance and will result in
hypertension.
● So any imbalance of the two pathways will cause hypertension.
New Classification of BP:
N: <120/<80
Elevated: 120-129/<80
High BP Stage 1: 130-139/80-89
High BP Stage 2: 140 or higher/90 or higher
Hypertensive Crisis: Higher than 180/Higher than 120
PATHOPHYSIOLOGY OF HYPERTENSION
& KIDNEY DISEASE
Table on page 2
● When you have an increase in blood pressure, you will have vessel damage and increase in intraglomerular pressure which leads to glomerular damage.
○ Glomerular damage results in proteinuria and microalbuminuria, which decrease the perfusion (due to decreased protein) and results in edema.
● Initially the glomerular filtration is maintained, however with subsequent damage, it will result to damage in glomerulus, endothelial cell proliferation and it will now stimulate the kidney to stimulate the Renin-Angiotensin-Aldosterone System (RAAS)
○ RAAS will now increase the sympathetic nerve activity and release the catecholamines, epinephrine and norepinephrine, and thus increase the heart rate and increase the blood pressure.
● At the same time, decrease in renal blood flow, because of the activation of the RAAS, will increase the tubular sodium reabsorption and will lead to the decrease
in the glomerular filtration rate as well as renal insufficiency leading again to hypertension.
○ It is a vicious cycle.
What organ contributes to the BP control via mechanisms on blood volume regulation?
Kidney
Kidney on Increased BP
compensatory mechanism in Sodium excretion —> decrease blood volume and decrease cardiac output —> decrease Blood pressure back to normal.
Kidney on Decrease BP:
increase sodium/water reabsorption —>
stimulates renin secretion —> Angiotensin II production —> renal artery constriction + aldosterone secretion —> increase sodium water reabsorption = increase blood pressure to normal.
In what situation is when your system cannot cope up, if not careful and increase rehydration?
Severe hypovolemia
the patient might end up in hypovolemic shock.
Managemen of Hypertension in a Nonpharmacologic Approach:
● Precedes drug reaction mild hypertension.
● Weight loss
● Sodium intake (5-6g/dl)
● Increase aerobic exercise (>30 min/day)
● Moderate consumption of alcohol
● Smoking cessation
● Increase consumption of fruits, vegetables, and low-fat dairy products.
Goals of Therapy
● To lower Blood pressure
● To reduce risk of target organ damage (TOD)
What are the anatomic sites of BP control?
● Arterioles
● Postcap Venules
● Heart
● Kidney
Modification table on page 2
Increased physical activity, recommended is
4-5x per week
Moderate alcohol intake, recommended is
Red wine - 1 small glass.
○ Beer is not included due to high carbohydrate content but they can be considered by drinking 12 oz.
○ Wine (5 oz.), 80 proof liquor (1.5 oz) each will represent an average 14 grams of ethanol.
All antiHPN agents act at one or more of these anatomic sites
Interfere with normal mechanisms of BP regulation
It lowers BP by increasing urine outflow
○ Deplete the body of Na and lower blood volume
Diuretics
It lowers BP by decreasing peripheral vascular resistance.
○ Inhibits heart function and increase venous pooling in capacitance vessels
Sympatholytics/Sympathoplegics
What can relax vascular smooth muscles
thus dilating resistance vessels?
Direct vasodilators
It blocks angiotensin production and action
○ Decrease PVR and blood volume
Angiotensin inhibitors
These antihypertensives act by different mechanisms and allow the combined use of 2 or more drugs. For what?
○ Increase efficacy and mild toxicity
○ Many hypertensive people, especially older people are the ones who need more than one medication because they are the ones whose blood pressure take longer time to decrease.
