Diuretics Flashcards

1
Q

What happens to water if we block Na resorption into the blood?

A

More water leaves in the urine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What does higher blood volume cause?

A

Higher blood pressure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

How much volume is filtered in Bowman’s capsule?

A

20%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

How much fluid filtered in Bowman’s capsule gets resorbed?

A

> 19%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

How much plasma entering the kidney get sent back into circulation and how much gets excreted?

A

> 99% back into circulation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is the site of action for diuretics?

A

Nephron

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What does Carbonic anhydrase do?

A

Facilitates Na reabsorption and H20 retention

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Osmotic diuretics

A

A type of diuretic that inhibits reabsorption of water and sodium
Pharmacologically inert substances that are given intravenously
Increase osmolarity of blood and renal filtrate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Where do osmotic diuretics act?

A

Proximal convoluted tubule and

Proximal straight tubule

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Loop diuretics

A

Act on the ascending loop of Henle
Primarily used in meds that treat hypertension and edema often due to congestive heart failure and renal insufficiency
More effective in patients with impaired kidney function

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is the site of action of loop diuretics

A

Thick ascending loop of Henle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is the mechanism of how Loop Diuretics work?

A

Should be excreted in the lumen
Inhibits Na, K, 2Cl transporter –> this significantly increases the excretion of Na, K, and Cl
Osmotic gradient for water resorption is also decreased –> Increasing water excretion
Ca and Mg are excreted as well

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What site do Thiazide diuretics act on?

A

Distal convoluted tubule

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is the mechanism of how Thiazide diurtics work?

A

Secreted by Proximal tubules but work in the distal convoluted tubules
Inhibit Na-Cl symporter from the lumen to tubular cells –> this increases Na and Cl excretion (and water)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

K+ sparing diuretics site of aciton

A

Collecting tubule

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Potassium sparing diuretics

A

Do not promote the secretion of potassium in the urine
Used as adjunctive therapy (together with other drugs) in the treatment of hypertension and management of congestive heart failure
Used with other drugs that would otherwise tend to lower K levels

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Potassium sparing diuretics mechanism of aciton

A

Competitive antagonist that either compete with aldosterone for intracellular cytoplasmic receptor sites
or
Directly block sodium channels
These cause for a lack of stimulation of Na-K exchange sites in the collection tubules, preventing Na reabsorption and K secretion

18
Q

What is blood pressure the measurement of?

A

The force applied to artery walls

19
Q

Systolic

A

When the ventricles contract

20
Q

Diastolic

A

When ventricles are relaxed

21
Q

Mean Arterial Pressure

A

MAP = CO x TPR

22
Q

Cardiac Output

A

Stroke volume x HR

23
Q

What is responsible for short term BP regulation

A

Sympathetic nervous system

24
Q

What is responsible for long term BP regulation

A

Renal system

25
Q

Baroflex regulation of blood pressure

A

Baroreceptors send blood pressure information to the medulla

Sympathetic nerves adjust the catcholamines to regulate vasoconstriciton, heart beat, and CO

26
Q

How does the kidney sense blood pressure?

A

Juxtaglomerular cells have baroreceptors, sense low renal blood blow, and secrete renin

27
Q

Renin

A

Enzyme resonsible for Angiotensinogen to be converted to Angiotensin I

28
Q

Angiotensinogen

A

Produced by the liver
Converted to Angiotensin I by Renin
Angiotensin I is converted to Angiotensin II by Angiotensin converting enzyme (ACE)

29
Q

Angiotensin II

A

Mediates direct and indirect vasoconstriction, sodium reabsorption and water retention
Can also produce structural remodeling
Promotes aldosterone release from the adrenal cortex

30
Q

Which Angiotensin II receptor is the site of drugs to treat hypertension?

A

AT1 receptor

31
Q

What drugs can be used to treat hypertension?

A

Diuretics
Sympathoplegic agents
Direct vasodilators
Block Angiotensin II production or activity

32
Q

Sympathoplegic agents

A

Act on CNS
Reduce release of epinephrine from sympathetic nerve endings
Block selective adrenoreceptors

33
Q

Sympathoplegic agent side effects

A

Sedation, depression, sleep disturbances
Static hypotension
Selective side effects

34
Q

What is the mechanism of Sympathoplegic agents acting on the CNS

A

Activate a2 receptors in the CNS

Diminishing central sympathetic outflow, and reducing cardiac output

35
Q

How do Sympathoplegic act to block selective adrenoreceptors

A

They block B2 receptors to diminish CO and Renin produciton

They can also block a1 receptors to block voasoconstriction (can cause Na and water retention - need a diuretic)

36
Q

What mechanisms can Direct vasodilators work?

A

1) Nitric oxide pro-drugs or drugs that promote NO release form the endothelium
2) Reduce Ca influx to vascular smooth muscle
3) Hyperpolarization of vascular smooth muscle (by openign K channels)
4) Activation of dopamine receptors

37
Q

How can direct vasodilators reduce Ca influx to vascular smooth muscle cells?

A

Block L-type Ca channels

Used in treatment of angina, hypertension, and arrythmias

38
Q

Drugs that cause Hyperpolarization of vascular smooth muscle mechanism

A

Activates K channels causing hyperpolarization of smooth muscle cells
Diminishes Ca levels and contraction

39
Q

Direct vasodilators activating dopamine receptors

A

Produce effects similar to B2 adrenergic receptor agonists on bronchial smooth muscle
Used in emergency and post-op treatment

40
Q

How can hypertension drugs block angiotensin II production activity?

A

1) ACE inhibitors
2) Competitive antagonists of angiotensin receptors
3) Renin inhibitors
4) Aldosterone inhibitors

41
Q

ACE inhibitors

A

Prevent Angiotensin I from becoming Angiotensin II

Also degrades bradykinin, which is a vasoconstrictor, so they also promote vasodilation

42
Q

Competitive antagonists of angiotensin receptors

A

Block AT1 receptor