Diuretics and RAAS Antagonists Flashcards
Nitrates dilate the _________ and hydralazine dilates the _________.
veins; arteries
Why do ACE inhibitors and aldosterone-receptor antagonists cause hyperkalemia?
Because aldosterone lowers serum potassium levels, so blocking its action leads to hyperkalemia
Low serum potassium leads to _________ conductance.
decreased
High serum potassium leads to _________ conductance.
increased
Hypokalemia can lead to _____________ in the heart.
U waves and ectopic pacemakers
The most worrisome side effect of loop diuretics is ___________.
hypokalemia
There are two classes of potassium-sparing diuretics: _____________.
aldosterone-receptor antagonists and collecting tubule sodium channel blockers
Sprionolactone is an _____________.
aldosterone receptor antagonist
Some people have endocrine effects with spironolactone, so ________ is used instead.
eplerenone
Loop diuretics like furosemide act on the ____________ division of the loop of Henle.
ascending
Aldosterone is a __________ that acts on the _________ part of the kidney.
hormone; collecting duct
Thiazides work on the ______________.
distal convoluted tubule
Excess intracellular potassium ions in the cells of the ascending loop leads to a potential that ____________.
drives the entry of magnesium and calcium ions
Because furosemide inhibits the Na/KCl pump–which then decreases the potassium potential–one side effect of furosemide and other loop diuretics is ____________.
hypomegnesemia and hypocalcemia, because the potassium potential is needed to drive the entry of these ions from the lumen to the intracellular environment
__________ can ameliorate potassium wasting.
Aldosterone antagonists
In contrast to loop diuretics, thiazide works by ____________.
inhibiting the NaCl symporter; this drives the NCX on the basolateral side of the cell to pump calcium into the blood and sodium into the cell, thus increasing calcium absorption
Thiazides can precipitate a gouty attack, because they ___________.
compete for the same organic acid secretory system as uric acid, thus raising uric acid levels
Aldosterone stimulates a receptor in the collecting tubule that _____________.
resorbs sodium and expels potassium; thus, inhibiting this transporter causes excretion of sodium and increased retention of potassium
_________ also decrease bradykinin activation, further enhancing vasodilation.
ACE inhibitors
All ACE inhibitors are administered as _________.
prodrugs that get activated by the liver, except lisinopril and captopril
Ibuprofen and naproxen have the potential to ___________.
exacerbate heart problems
What are the three main goals of pharmacologic heart-failure management?
Reduce congestion, improve flow, and modulate neurohormonal activation
All heart failure patients need to take __________, but only more some will take __________, depending on symptoms.
ACE inhibitors and ß-blockers; ARBs, vasodilators, or diuretics
Angiotensin receptor blockers (ARBs) are used in patients intolerant to ___________.
ACE inhibitors
The effect of serum potassium on conductance is paradoxical: low potassium leads to _________, while high potassium leads to ___________.
decreased conductance (because of increased electrochemical potential); increased conductance (because of decreased electrochemical potential)
What levels of potassium lead to increased ectopic arrhytmogenesis?
Hypokalemia
Hyperkalemia leads to ________ heart rate.
bradycardiac (because of decreased conductance)
People who are hypokalemic should not be given drugs that __________ heart rate.
increase
What is the mechanism for thiazide-induced hypokalemia?
It increases the luminal concentration of sodium in the distal convoluted tubule, thus causing more Na/K exchange in the collecting tubule.
_________ can cause hyperkalemia when given with ACE inhibitors.
Aldosterone receptor antagonists
ACE inhibitors also inhibit __________, further increasing their vasodilator effects.
bradykinin
Losartan is the only angiotensin II receptor antagonist that is dosed __________.
twice daily
Decreased losartan dose is necessary in ______ dysfunction.
hepatic
