Cardiovascular Drugs Flashcards
What is the SBP and DBP for a normal person?
SBP: <120
and
DBP: <80
What is the SBP and DBP of prehypertension?
SBP: 120-139
or
DBP: 80-89
What is the SBP and DBP of a person with stage 1 hypertension?
SBP: 140-159
or
DBP: 90-99
What is the SBP and DBP of a person with stage 2 hypertension?
SBP: >160
or
DBP: >100
What is essential hypertension?
-hypertension where the cause is unknown
-occurs in 90-95% of cases
-treated symptomatically
What is the biggest problem with high blood pressure?
stroke
If the cause of hypertension is known, what is it called?
secondary hypertension
What are 4 possible causes of secondary hypertension?
-sleep apnea
-thyroid disease
-Cushing’s syndrome
-chronic kidney disease
What are 4 systems that could have complications due to hypertension?
-cardiovascular system
-CNS
-Renal system
-Retinal damage
What organ damage can occur from hypertension?
-Heart: myocardial infarcts, failure, coronary disease
-Brain: stroke, ischemic attacks
-Kidneys: chronic disease, failure
-Retinopathy
What are 4 contributing factors to hypertension?
-obesity
-stress
-diet
-smoking
What is the equation for Mean Arterial Pressure?
MAP = CO x PVR
-CO = HR x SV
What factors affect cardiac output (CO)?
-blood volume
-heart contactility
-venous tone
What things affect pulmonary vascular resistance (PVR)?
-myogenic tone
-vascular responsiveness
-vasoactive metabolites
-nervous control
What does a decrease in blood pressure directly lead to?
-increase in sympathetic activity
-decreases in renal blood flow
What does an increase in sympathetic activity cause?
-activates b1 adrenoceptors in heart
-activates a1 adrenoceptor in SM
-activates b1 adrenoceptors on kidney
What does a decrease in renal blood flow cause?
-Renin release
-decrease in glomerular filtration rate
What does renin release cause?
-increase in angiotensin 2
What two things cause renin release?
-decrease in renal blood flow
-activation of b1 adrenoceptor of kidney
What increase in angiotensin 2 cause?
-increased peripheral resistance
-increased aldosterone
What does activation of b1 heart adrenoceptors cause?
-increased cardiac output
What does activation of a1 SM adrenoceptors cause?
-increased venous return
-increased peripheral resistance
What does aldosterone do?
increase sodium and water retention
what does increased sodium and water retention cause?
increased blood volume
What three things ultimately cause increase in BP after a drop?
-increased cardiac output
-increased venous return
-increased peripheral resistance
What are the 7 categories of antihypertensives?
-angiotensin 2 receptor blockers
-renin inhibitors
-calcium channel blockers
-a-blockers
-ace inhibitors
-b-blockers
-others
What do ACEI’s do?
-angiotensin-converting enzyme inhibitor
-stop the converting enzyme from changing angiotensin 1 to 2
- reduce symp NS tone
- incr. vasodilator tone = dec. in vascular resistance from decreased Ang2 and catecholamines
- reduced Na and water retention because of less ang2 and less aldosterone
What is the pathway of angiotensinogen to AT1/2?
angiotensinogen -> angiotensin 1 via renin -> angiotensin 2 via converting enzyme -> AT1 and AT2 (aldosterone)
List 5 adverse effects of ACEIs
-postural hypotension
-hyperkalemia
-renal insufficiency
-persistent dry cough
-contraindication in pregnancy
What are the three types of beta blockers?
-1st generation = nonselective
-2nd generation = b1 cardioselective
-3rd generation = additional CV action
What is the relationship between a1 and b2 adrenoceptors?
a1 job is the opposite of b2
What is the proposed mechanism for beta blockers?
- block cardiac b1 receptor -> lower CO
- block renal b1 receptor -> lower renin, lower PVR, decreases SNS output
What is special about carvedilol and labetalol? why is it still used?
-is is very non specific
-it blocks alpha and beta receptors
-used because blocking alpha = induces bronchodilation and vasodilation
What are the common adverse effects of vasodilator drugs?
-fall in BP = reflex tachycardia
-fall in BP = renin -> Na/H2O retention
What are three categories of vasodilator drugs?
- calcium entry blockers
- potassium channel openers
- direct-acting vasodilators
What two calcium blocking drugs do not have reflex tachycardia as an adverse effect?
-no reflex tachycardia with verapamil and diltiazem because they directly block Ca channel in heart
-nifedipine doesn’t work on heart, just vascular system
-can’t have reflex tachycardia without Ca+ channels in heart
Why is nifedipine not useful as an antiarrhythmic drug?
because it is a dihydropyridine and they only work on vascular Ca channels of aorta SM and veins
What drugs can be used in hypertensive emergencies?
-labetalol iv
-diazoxide iv
-Na-nitroprusside iv
What are diuretics?
-a substance that promotes urine excretion
-caffeine, alcohol, cranberry juice
What are natriuretics?
-substances that promote renal excretion of Na+
What is the order of structures in the nephron?
glomerulus -> proximal convoluted tubule -> descending loop of Henle -> ascending loop of Henle -> distal convoluted tubule -> collecting duct
What does aldosterone do?
increase the reabsorption of sodium and water and increase BP
What part of the nephron does acetazolamide work on?
proximal convoluted tubule
What part of the nephron does furosemide work on?
ascending loop of Henle
What part of the nephron do thiazides and thiazide-like drugs work on?
distal convoluted tubule
What part of the nephron does spironolactone work on?
collecting duct
What is secreted into and reabsorbed from the proximal tubule?
-secreted: organic acids
-reabsorbed: Na, K, H2O
What is secreted into and reabsorbed from the ascending loop of Henle?
-secreted: none
-reabsorbed: Na, K, Cl
What is secreted into and reabsorbed from the distal convoluted tubule?
-secreted: none
-Reabsorbed: Cl, Na
What is secreted into and reabsorbed from the collecting duct?
-secreted: H+, K
-reabsorbed: Na, H2O
