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HTN Pharm Test
Question | Answer |
---|---|
What are some complications of hypertension? | stroke, cerebral hemorrhage, heart failure, MI, angina, kidney disease |
Risks decreased? | stroke 35-40%, MI 20-25%, heart failure greater than 50% |
Influences on HTN? | 1. HR, 2. myocardial contractility, 3. blood volume, 4. venous return to the heart |
sympathetic baroreceptor reflex | 1. baroreceptors in aortic arch and carotid sinus sense BP, send to BS 2. perceived too low BS sends message through SNS to stimulate heart and blood vessels 3. BP elevated by alpha 1 receptors->vasoconstriction 4. when "normal" BP-stimulation stops |
How is the "set-point" set in HTN? | it is set high |
what does the high set-point cause in HTN? | the body resists drugs to lower BP by activation of SNS to return to the high set point resulting in reflex tachycardia and vasoconstriction |
Can the set-point be lowered? | yes, with long term therapy |
Renin-Angiotensin-Aldosterone system: What causes release of renin? | reduced renal blood flow, reduced blood volume, reduced BP, and activation of beta 1 adrenergic receptors on the cell surface |
What does renin do? | promotes the conversion of angiotensinogen into angiotensin I |
what acts on angiotensin I to form angiotensin II? | angiotensin-converting enzyme (ACE) |
how does angiotensin II elevate blood pressure? | it increases peripheral resistance, and also causes release of aldosterone from adrenal cortex |
What does renal blood vessel constriction do? | reduces GFR causing retention of salt and water (increasing BP and blood volume) |
how does renal regulation happen? | lower GFR, retention of sodium, chloride, and water- increased volume, increased cardiac output, increased BP |
what does dilation of arterioles do? | reduces vascular resistance |
what does dilation of veins do? | reduces venous blood flow to the heart |
What is the first line treatment of HTN in all? | diuretics |
how do thiazides work? | increase renal excretion of sodium, chloride, and water. also elevate plasma levels of uric acid and glucose. |
Do thiazides work on people with renal disease? | No, it is dependent on adequate kidney function. Will not work with low GFR |
What is the most commonly used thiazide? | hydrochlorothiazide (HCTZ) |
how does HCTZ work? | promotes urine production by blocking the reabsorption of sodium and chloride in the early segment of the distal convoluted tubule |
when does diuresis begin, peak, and what is the duration? | Begins in 2 hours, peaks in 4-6, and lasts up to 12 hours |
who should you use caution with giving thiazides? | people with gout, diabetes, |