Pharmacology - Diuretics Flashcards
how can endothelial cell damage lead to high blood pressure
endothelial cells (healthy) would normally release nitric oxide - a vasodilator. if the endothelial cells are damaged, there will be no nitric oxide release and the arteries will become stiff and blood flow hindered - INCREASED RESISTANCE
increased load on the heart due to high BP can cause…
CHF
true or false
if HTN is asymptomatic, it does not need to be treated
FALSE i it does
name 3 classes of diuretics
thiazides
loop diuretics (high ceiling)
potassium sparing
MOA diuretics
act on the kidneys to increase excretion of sodium and water
this decrease in blood volume causes decreased blood pressure
name 2 thiazide diuretics
hydrochlorothiazide
chlorthalidone
name 2 high ceiling loop diuretics
furosemide and torsemide
name 3 potassium sparing diuretics
spironolactone
triamterene
amiloride
MOA ACE inhibitors
how to recognize them?
anything ending in “pril”
inhibits conversion angiotensin 1 to angiotensin 2 by inhibiting ACE enzyme
this causes decrease in vasoconstriction, reduces peripheral resistance, and lowers BP
what are AT1 blockers and what is their MOA
inhibit angiotension 2 binding to its receptor (AT1)
called “ARBS”
all end in “artan”
name 2 centrally acting antihypertensives and their MOA
clonidine, methyldopa
act (agonists) on CENTRAL alpha 2 receptors to decrease sympathetic outflow, and thus cause a fall in bp
true or false
a2 causes vasodilation so clonidine and methyldopa are agonists to it
true
a1 causes constriction
nonselective beta blocker
what is MOA
propranolol
binds beta adrenergic receptors and BLOCKS activity
explain how labetolol and carvedilol work
bind B1 receptor in heart and BLOCK IT — blocks firing of SA node and reduces heart rate
cardioselective beta blocker
metoprolol
verapamil class
calcium channel blocker (NON dihydro pyridine)
name 3 alpha adrenergic blockers and their MOA
prazosin, terasozin, doxasozin
block alpha adrenergic receptors in smooth muscle to cause vasodilation
explain MOA calcium channel blockers
block influx of calcium into smooth muscle cells —- reduced contraction – decreased BP
**name 4 thiazide diuretics
chlorthalidone
hydrochlorothiazide
indapamide
metolazone
thiazide diuretics can also be called…
naturetics
___ are also called water pills. why?
diuretics
bc they remove more water through the urine
some things diuretics can treat
hypertension
edema
heart failure
***where do thiazides work within the nephron?
DCT - distal convoluted tubule
***EXPLAIN the full mechanism of thiazide diuretics
directly block the reabsorption of sodium and chloride into the body at the 1st portion of the DCT
they do this by inhibiting a sodium/chloride symport cotransporter
by inhibiting sodium entry, calcium reabsorption is ENHANCED
diuretics will _____:
-sodium levels
-potassium levels
-calcium lvels
decreased sodium and potassium
increased calcium levels
true or false
thiazide diuretics enhance the excretion of sodium and chloride in the urine
true
thiazide diuretics DECREASE the urinary excretion of _______
calcium
true or false
thiazide diuretics work in the collecting duct
FALSE - DCT
true or false
thiazide diuretics increase calcium reabsorption
TRUE
thiazide diuretics cause ___ metabolic ____
hypokalemic metabolic alkalosis
molecular target of thiazide diuretics
the sodium/chloride symport cotransporter
true or false
the sodium and potassium lost in the urine due to thiazide diuretics is a passive loss
true
*****5 contraindications for HCTZ and explain
-gout (bc uric acid levels will be elevated)
-diabetes (elevates glucose)
bc potassium needed to convert proinsulin to insulin, and diuretics deplete potassium
-hypokalemia
-sulfonamide allergy
-renal failure
***_______ can occur when taking diuretics because diuretics cause sodium depletion, which increases _____ reabsorption
LITHIUM TOXICITY
INCREASED LITHIUM REABSORPTION
**thiazide diuretics cause ____ kalemia
what are the symptoms?
hypo
muscle pain and fatigue
**thiazide diuretics cause ____ glycemia
why
hyperglycemia
potassium depletion – no conversion of proinsulin to insulin
** thiazide diuretics cause _____ lipidemia
hyperlipidemia
rise in LDL —- risk of stroke
**thiazide diuretics cause _____ uricemia
hyperuricemia
bc urate excretion is inhibited
**thiazide diuretics can cause sudden cardiac ____
DEATH
bc of hypokalemia – heart rate affected
all of the AE of thiazide diuretics listed are really only relevant when?
what is conclusion that the JNC made**
at HIGH DOSES – very minimal AE with low doses of 12.5-25
start low dose thiazide therapy in HTN. if this therapy fails, try another antihypertensive along with it. DO NOT INCREASE THE THIAZIDE DOSE!!!!!!!
___diuretics are to be given when there is severe hypertension with retention of body fludis
loop diuretics
*** thiazides can cause metabolic ________
ALKALOSIS
____ is thiazide like diuretic
chlorthalidone
true or false**
chlorthalidone has a different MOA than thiazides
FALSE - same
even tho thiazide like
inhibits Na/Cl symporter at DCT
CV reaction to chlorthalidone
orthostatic hypotension
indapamide class
thiazide-like diuretic
metolazone class
thiazide-like diuretic
true or false
potassium sparing diuretics and thiazide/thiazide-like diuretics cannot be used together
FALSE
they can be used together to replenish potassium lost by thiazides
other than _____, potassium sparing diuretics are primarily used with thiazide diuretics
other than spironolactone
“a class of drugs that helps the body to get rid of excess sodium and water without losing potassium in the urine”
potassium sparing diuretics
true or false
k+ sparing diuretics have a different MOA than thiazide and thiazide-like diuretics
TRUE
name 4 potassium sparing diuretics
amiloride
eplerenone
spironolactone
triamterene
amiloride inhibits ____
enac
blocks epithelial sodium channel in the DCT
besides amiloride, what other drug inhibits enac
triamterene
____ is the metabolite of spironolactone and has the same MOA
eplerenone
potassium sparing diuretics work where in the nephron?
the collecting duct
explain how aldosterone antagonists like spironolactone and eplerenone work
normally, aldosterone would bind its receptor and work to retain water
however, aldosterone antagonists bind the aldosterone receptor instead
the expression of enac channels is regulated by what?
aldosterone
potassium sparing diuretics can cause ___ kalemia and ____osis
hyperkalemia and acidosis
true or false
aldosterone increase enac expression
TRUE
more enac expression = more sodium influx and more water retained
true or false
aldosterone antagonists cause a loss of sodium and water
true
3 major advantages of spironolactone over HCTZ
no hypokalemia, hyperglycemia, hyperuricemia
**2 major AE of potassium sparing diuretics like spironolactone
hyperkalemia
metabolic acidosis
*****metabolite of spironolactone
when is its use beneficial?
eplerenone
in liver failure! it bypasses hepatic metabolism
