Exam 1; Diuretics Flashcards Preview

AU14 Pharmacology > Exam 1; Diuretics > Flashcards

Flashcards in Exam 1; Diuretics Deck (37)
Loading flashcards...
1
Q

What is the definition of a diuretic

A

any agent that causes a net excretion of water and Na+

2
Q

What two main things are diuretics used for clinically

A

hypertension; decreasing blood volume and some cause vasodilation
to reduce edema; in heart failure; kidney retains H2O and Na, water accumulates in the interstitial space

3
Q

This is designed to eliminate unwanted molecules (Na & H2O) and to conserve essential ions and molecules

A

normal kidney function

4
Q

What is the flow of molecules in the proximal convoluted tubule

A

removal of Ca++, Na+, HCO3-

exchange of organic molecules

5
Q

What is the flow of water through the renal tubule

A

water can freely pass through the tubule; following the osmotic gradient

6
Q

What is the flow of molecules in the loop of Henle

A

removal of K+, Cl-, and large amounts of Na

7
Q

What is the flow of molecules in the distal convoluted tubule

A

removal of Na+, Cl-, Ca++

8
Q

What is the flow of ions in the collecting duct

A

Na+/K+ exchanger (Na out, K in)

removal of H2O

9
Q

True or False

Thiazide diuretics have a low therapeutic index

A

False; they have a high index

10
Q

What is the mechanism behind thiazide diuretics

A

they inhibit Na+ transport out of the DCT; water follows and they are excreted in the urine

11
Q

What are two other affects of thiazide diuretics

A

they cause direct vasodilation (often drug of choice in treating hypertension)
they decrease the excretion of Ca++ (Ca++ retention)

12
Q

What are five side effects of thiazide diuretics

A

hypokalemia (loss of Ka due to Na/K exchanger)
increase serum LDL and triglycerides
decrease uric acid secretion; gout
inhibit insulin secretion
contains sulfur ions; may cause allergic reaction

13
Q

What are two examples of thiazide diuretics

A

chlorothiazide

hydrochlorothiazide

14
Q

What are four examples of loop/high ceiling diuretics

A

furosemide
ethacryncic acid
bumetanide
torsemide

15
Q

What is the mechanism of action of loop diuretics

A

given orally or parentally

inhibit Na/Cl resorption from the ascending limb of the loop of Henle

16
Q

Which is more efficacious, thiazides or loop diuretics

A

loop

17
Q

How much urine/day can a patient excrete while on loop diuretics

A

10L

18
Q

When are loop diuretics given clinically

A

in patients that don’t respond well to thiazides
patients with impaired renal function
patients with life threatening edema (pulmonary/cerebral)

19
Q

What are 5 side effects of loop diuretics

A
dehydration
hypokalemia (more Na to exchanger)
hypocalcemia (increase Ca excretion)
decreased uric acid secretion
auditory nerve damage (especially if used with other ototoxic agents)
20
Q

What are two examples of potassium-sparing diuretics; aldosterone antagonists

A

spironolactone

eplerenone

21
Q

What is the mechanism behind potassium-sparing diuretics

A

blocking the aldesterone receptor; can prevent synthesis of Na/K+ exchanger

22
Q

What are four side effects of potassium-sparing diuretics

A

takes a couple days to work
used with other diuretics to prevent K+ loss
used to treat excess aldesterone activity
can cause hyperkalemia

23
Q

This potassium-sparing diuretic is a steroid, and can have anti-androgen effects (breast growth, etc.)

A

spironolactone

24
Q

This potassium sparing diuretic has fewer interaction with other steroid receptors

A

eplerenone

25
Q

These two potassium-sparing diuretics are inhibitors of what

A

triamterne
amiloride
Na+ transport in the distal tubule and collecting duct

26
Q

Potassium-sparing diuretics which inhibit Na transport have what kind of mechanism

A

they prevent Na from getting into the exchanger by blocking Na channel

27
Q

What is the effect/symptoms of potassium sparing diuretics which inhibit Na transport

A

the effect is more rapid and predictable than alderstone antagonists
hyperkalemia

28
Q

What is the mechanism behind carbonic anhydrase (enzyme) inhibitors

A

inhibits HCO3- absorption in the PCT

29
Q

What three things do carbonic anhydrase inhibitors (not primarily a diuretic) also treat

A
open angle glaucoma
mountain sickness (decrease CSF formation)
epilepsy (may be due to pH changes in the CNS)
30
Q

This is an example of an osmotic diuretic

A

mannitol

31
Q

What is the mechanism behind mannitol

A

non-metabolized sugar given as an IV and it remains in tubule and draws water into tubule and is secreted with the water

32
Q

What is mannitol used to treat

A

used to maintain renal/urine flow after renal damage/trauma

also it lowers intracranial pressure

33
Q

This diuretic increases globular filtration rate

A

methylxanthines (such as caffeine)

34
Q

This diuretic releases ADH

A

ethanol

35
Q

This triggers the synthesis of the Na/K exchanger

A

aldesterone

36
Q

ADH (antidiuretic hormone) induces what

A

further reabsorption of H2O

37
Q

This blocs the ADH receptor; in cases of excess ADH/retain too much water

A

conivaptin