27 - diuretics

Question 1

what happens if we block Na+ reabsorption into the blood

Answer 1

more water leaves in urine

lowers BP

Question 2

Kidneys filter 180 liters of plasma per day

Produce _ liters of urine per day

Answer 2

1.5 liters of urine

<1% of volume is excreted via urine

Question 3

Carbonic Anhydrase facilitates Na+ and -
HCO3 _
(and H2O _)

Answer 3

Na+ and -
HCO3 reabsorption

H2O retention

Question 4

Carbonic anhydrase activity will:
1. Provide protons for H+/Na+
exchange
2. Provide HCO3
- for Na+ cotransport
to blood

net? CO2 plus water from lumen yields _ in blood and _ in urine

Answer 4

Net: CO2 plus water from lumen yields Na+CO3 in
blood;

H+ in urine

Question 5

Inhibition of carbonic anhydrase inhibits _ reentry

and enhances _ loss, water follows Na+

Answer 5

inhibits Na+ reentry
(and enhances fluid loss, water follows Na+)

decreasing volume thus decreasing BP

Question 6

where do carbonic anhydrase inhibitors (diuretic) site of action

Answer 6

proximal convolutaed tubule

most of Na is reabsorbed here and it blocks the reuptake of Na leading to more sodium in urine (means more water leaving)

Question 7

_ diuretic is a type of diuretic that inhibits reabsorption of water and sodium. They are
pharmacologically inert substances that are given intravenously. They increase the osmolarity of blood
and renal filtrate. Two examples are mannitol and
isosorbide.

Answer 7

An osmotic diuretic

*mannitol filtered out but not well resorbed

water follows mannitol - which is in urine

Question 8

where do osomtic diuretics site of action

what part of nephron

Answer 8

PCT, thin descending and thin ascending limbs

water follows mannitol

Question 9

where do loop diuretics works in the nephron

Answer 9

thick ascending limb

Question 10

Loop diuretics are diuretics that act at the
ascending loop of Henle in the kidney on _. They are primarily used in medicine to treat _ and _ often due to congestive heart failure or
renal insufficiency.

Answer 10

inhibs Na,K,2Cl symporter - significantly increases the excretion of these ions

hypertension
and edema

Question 11

_ diuretics are
more effective in patients with normal kidney function,

_ diuretics are more effective in patients with impaired kidney function

Answer 11

thiazide diuretics - normal healthy kidneys

loop diuretics - impaired kidney patients

Question 12

_ diuretics

inhibits Na,K,2Cl symporter - significantly increases the excretion of these ions - water follows

Answer 12

loop diuretics

Question 13

sulfonamide allery is a drug allery linked with use of _ diuretics

Ca and Mg are excreted as well so have to be careful about imbalances

Answer 13

loop diuretics

sulfonamide is in some antibiotics

Question 14

these diuretics work in the DCT , only 5-10% of Na reaborbed here

block the Na/Cl symporter, increasing Na and Cl excretion and water

Answer 14

thiazide diuretics

secreted by PCT but works in the DCT

can have weak CA-I effect as well

Question 15

Because loop and thiazide diuretics increase
sodium delivery to the distal segment of the
distal tubule, this increases _ loss,

the increase in distal tubular sodium concentration
stimulates the _-sensitive sodium
pump to increase sodium reabsorption in
exchange for potassium and hydrogen ion,
which are lost to the urine.
The increased
hydrogen ion loss can lead to metabolic
alkalosis. Part of the loss of potassium and
hydrogen ion by loop and thiazide diuretics
results from activation of the reninangiotensin-aldosterone system that occurs
because of reduced blood volume and arterial
pressure.

Answer 15

increases potassium loss(potentially causing hypokalemia)

aldosterone - stimulates Na/K ATPase

Question 16

Increased aldosterone stimulates

_ reabsorption and increases _ and _ ion excretion into the urine.

Answer 16

sodium reabsorption (water comes back in)

potassium
and hydrogen ion excretion

Question 17

_ diuretics work in collecting tubules and inhib Na channels or work on ADH receptor

Answer 17

potassium-sparing

inhib apical Na channel

antagonist to ADH - binds to its recept to decrease gene expression and reduce synthesis of Na channels in tubule or decreases # of Na/K ATPase pumps in basolateral membrane

Question 18

_ diuretics are diuretic drugs that do not
promote the secretion of potassium into the urine.
They are used as adjunctive therapy, together with other drugs,
in the treatment of hypertension and management of
congestive heart failure.

Answer 18

Potassium-sparing

The combination therefore helps maintain a normal
reference range for potassium.

Question 19

_ diuretics

inhib apical Na channel blocking reabsorption

antagonist to ADH - binds to its recept to decrease gene expression and reduce synthesis of Na channels in tubule or decreases # of Na/K ATPase pumps in basolateral membrane

Answer 19

K sparing

used as ADJUNCTIVE THERAPY

Question 20

This prevents sodium re-absorption and

potassium and hydrogen ion secretion.

Answer 20

K sparing diuretics

binding to ADH receptor prevents the production of proteins that are normally
synthesized in reaction to aldosterone. These mediator proteins are not
produced, and so stimulation of sodium-potassium exchange sites in the
collection tubule does not occur. This prevents sodium re-absorption and
potassium and hydrogen ion secretion.

Question 21

_ diuretic

PCT, Loop of Henle, Collecting duct

inhibition of water and Na reabsorption

Answer 21

osmotic

can really increase the production of urine - literally loss 20 pounds in 1-2 ddays

Question 22

_ diuretic

PCT

inhibition of bicarbonate reabsorption

Answer 22

carbonic anhydrase inhibitors (CA-I)

Question 23

_ diuretic

thick ascending limb

inhib of Na,K,Cl cotransport

Answer 23

loop diuretics

Indirect effect - inhibit recapturing Mg and K+ = therapeutically - can lead to Mg and Ca imbalances - loop diuretics

Question 24

_ diuretic

early distal tubule

inhib of Na,Cl contransport

Answer 24

Thiazide

Question 25

_ diuretic

late distal tubule, Collecting duct

inhibition of Na+ reabsorption and K+ secretion (keeps K)

Answer 25

K sparing diuretics

Question 26

Blood goes into the _ and is filtered
Everything gets filters exceppt proteins
Then things get selectively put back into blood

Blood pressure needs to be there for this to work
Kidney regulates blood pressure as well

Answer 26

glomerulus

Question 27

Because of location of action Both _ and _ diuretics increase potassium loss

Take potassium Cl pill - banana won’t give enough
So if patient is taking potassium Cl pill - they are probably taking a BP med that is depleting of K because keeping Na out

Becasuse of this = Stimulates  a Na pump to increase sodium resorption in exchange for K and protons  This pump is sensitive to aldosterone

Answer 27

loop and thiazide

why it is nice to give K sparing diuretics in addition(decrease biosynthesis of the channel for Na and K