Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Clinical Pharmacology > 3.2 Diuretics > Flashcards

3.2 Diuretics Flashcards

1
Q

what are the four functions of the renal system?

A

regulatory
excretory
endocrine
metabolism

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

what are the regulatory functions of the renal system?

A

fluid balance
acid-base balance
electrolyte balance

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

what is the excretory function of the renal system?

A 
waste products (protein metabolism)
drug elimination (glomerular filtration and tubule secretion)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what is the endocrine function of the renal system?

A

renin
erythropoietin
prostaglandins
1-alpha calcidiol

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

what is the metabolic function of the renal system

A

vitamin D
polypeptides (insulin)
drugs (morphine and paracetamol)

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

what is the function of carbonic anhydrase inhibitors

A

reduce the absorption of NaHCO3 in the proximal convoluted tubule. Cause hypokalaemic metabolic acidosis initially but tolerance develops after a few days

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

what is the function of mannitol?

A

mannityol is an osmotic agent that causes diuresis. It has a high oncotic pressure and draws water into the lumen of the proximal convoluted tubule. Causes reduced intracellular pressure and a hypernatraemia risk

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

what is the function of SGLT2 inhibitors?

A

they inhibit the sodium glucose co transporter in the proximal convoluted tubules. This increases glucosuria and decreases plasma glucose levels. it also causes increased uric acid secretion and decreases plasma uric acid which helps in metabolic syndromes. other clinical findings include decreased body weight, decreased blood pressure and decreased glomerular hyperfiltration

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

what is the function of loop diuretics

A

loop diuretics act on the loop of henle to inhibit the Na/K/2Cl cotransporter. This results in the loss of sodium and water. It can cause hypokalaemic metabolic acidosis and increased calcium loss.

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

why do loop diuretics cause electrolyte disturbances?

A

usually K+ is transported into the cells of the thick ascending limb via the Na/K/2Cl cotransporter. This then allows back diffusion of the K+ through ROMK channels to create a positive luminal membrane. This positive charge provides a driving force for the absorption of divalent cations such as calcium and magnesium paracellularly. As loop diuretics inhibit the Na/K/2Cl cotransporter, this gradient isnt as strong and there is greater loss of calcium and magnesium.

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

what is the function of thiazide diuretics?

A

block the Na/Cl cotransporter in the distal convoluted tubule. This causes loss of sodium and water in urine. also causes hypokalaemic metabolic alkalosis and increased calcium reabsorption

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

why do thiazide diuretics cause increased calcium reabsorption?

A

as there is less sodium reabsorption, there is greater activation of the Na/Ca exchanger on the basolateral surface of the distal convoluted tubule cells. Calcium enters the cell via TRPV5 transporters.

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

why do thiazide diuretics cause alkalosis?

A

as less sodium is being reabsorbed, there is increased activation of the Na/H+ exchanger in the distal convoluted tubule resulting in a loss of hydrogen ions

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

what drug class is tolvaptan?

A

ADH antagonist

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

where is the site of action of amiloride?

A

the ENAC channels in the apical membrane of the principal cells of the collecting ducts

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

where is the site of action of spironolactone?

A

the intracellular aldosterone mineralcorticoid receptor in the principle cells of the collecting ducts

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

what is the mechanism of action of tolvaptan?

A

acts to block the V2 receptor of ADH on the cells of the collecting ducts. results in less aquaporin-2 channels and therefore less water reabsorption. as there is less water reabsorbed, less sodium is reabsorbed.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

what is tolvaptan used to treat?

A

hyponatraemia

prevent cyst enlargement in APCKD

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

How is lithium a diuretic?

A

used to treat bipolar disorder but also has the unwanted side effect of inhibiting ADH.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

what are the diuretic effects of alcohol and caffeine?

A

alcohol inhibits ADH release from the posterior pituitary

caffeine increases GFR and decreases tubular sodium release

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

what are some of the common ADRs of diuretics?

A

Hypovolaemia & hypotension
– Activates RAAS
– Can lead to acute kidney injury
Electrolyte Disturbance (Na+, K+, Mg2+, Ca2+)
Metabolic Abnormalities (depends on individual drug)
Anaphylaxis / photosensivity rash etc (rare)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

what are some of the common ADRs associated with thiazide diuretics?

A 
gout 
hyperglycaemia
erectile dysfunction
increased LDL and TG
hypercalcaemia
23
Q

what are some of the common ADRs associated with frusemide?

A

ototoxicity
alkalosis
increased low density lipoproteins and triglycerides
gout

24
Q

what are some of the common ADRs associated with spironolactone?

A

hyperkalaemia
impotence
painful gynaecomastia

25
Q

what are some of the common ADRs associated with bumetanide?

A

myalgia

26
Q

what is the drug class of bumetanide?

A

loop diuretic

27
Q

what are the potential interaction with lisinopril?

A

interact with K+ sparing diuretics to cause increased hyperkalaemia resulting in cardiac problems

28
Q

what are the drug interactions of loop diuretics?

A

aminoglycosides and loop diuretics interact to cause ototoxicity and nephrotoxicity

29
Q

what are the drug interactions of thiazide and loop diuretics?

A

both interact with digoxin, a cardiac glycoside to cause increased digoxin binding and toxicity
interact with steroids to cause hypokalaemia
interact with lithium to cause lithium toxicity with thiazides and reduced lithium with loop diuretics

30
Q

what drugs are used in treatment of hypertension?

A 
thiazide 
spironolactone
loop diuretics 
beta blockers
ACEi/ ARBs
31
Q

what drugs are used in the treatment of heart failure?

A
  • Loop diuretics
  • Spironolactone – non-diuretic benefits
  • ACE Inhibitors / Ang II antagonists
  • β-blockers
32
Q

what drugs are used in the treatment if decompensated liver disease?

A

spironolactone

loop diuretics

33
Q

what drugs are used in the treatment of nephrotic syndrome?

A

Loop diuretic (often big doses needed)
• +/- thiazides
• +/- potassium-sparing diuretic / potassium supplements

34
Q

how do we treat CKD?

A

the decrease in GFR leads to salt and water retention and patients become hyperkalaemic and acidotic. treat with loop diuretic and SGLT2s. Avoid potassium sparing diuretics

35
Q

what are the different stages of CKD?

A

stage 1 = 90% of the kidney functioning
2 = 90 to 60% of the kidney functioning
3 = 60 to 30 % of the kidney functioning
4 = 30 to 15% of the kidney functioning
5 = less than 15 % of the kidney functioning

36
Q

what factors can affect the functioning of furosemide?

A
  • gut oedema. can stop the absorption into the epithelial cell
  • CKD - furosemide is transported into the PCT epithelial cell via the OAT1 / 3 transporter that is non specific. In CKD the OAT is being used to transport other toxins across the renal tubule. Reduced amounts of nephrons
37
Q

why do thiazide and loop diuretics cause hyperuricaemia?

A

Competition at OATs is one mechanism particularly for thiazide like drugs and action at the URAT1 transporter is another. Cardinally their respective diuresis and hypovolemia increase the risk of uric acid crystal formation.

38
Q

describe how thiazide and loop diuretics cause hyponatraemia and hypokalaemia

A

Thiazide diuretics are more likely to cause hyponatraemia because they act at the distal convoluted tubule. They do not affect the medullary osmotic gradient. The thiazide diuretics inhibit Na reabsorption (the Na/Cl cotransporter is inhibited). Water is able to be reabsorbed at the collecting duct as the osmotic gradient has been maintained by the action of the Na/K/Cl cotransporter at the ascending loop. Water is reabsorbed (ADH action) and the relative Na concentration in the plasma is lower – more water proportionally to Na. With loop diuretics the osmotic gradient is disrupted because Na is not reabsorbed in the ascending loop (the Na/K/Cl cotransporter is inhibited). Because the gradient is lost, at the collecting duct less water is reabsorbed and so the relative Na concentration to water is maintained – less likely to observe hyponatraemia. It is the increased water reabsorption relative to Na that predominantly results in hyponatraemia, not a loss of Na. Both thiazide and loop diuretics can cause hypokalaemia as K is excreted (K channels) in exchange for Na (ENaC) in the collecting duct mediated by aldosterone

39
Q

what is Bartter’s and Gitelman’s syndrome?

A

inherited autosomal recessive conditions resulting in defects of renal tubular excretion and reabsorption of electrolytes.

40
Q

what is liddle’s syndrome?

A

autosomal dominant genetic disorder characterized by early, and frequently severe, high blood pressure associated with low plasma renin activity, metabolic alkalosis, low blood potassium, and normal to low levels of aldosterone. Excess reabsorption of sodium and loss of potassium from the renal tubule as there is increased function of the kidney

41
Q

what are the main uses of carbonic anhydrase inhibitors?

A

glaucoma

altitude sickness

42
Q

what are they main uses of osmotic diuretics?

A

reduce high intracerebral pressure

43
Q

what are the main uses of loop diuretics

A

oedema

hypertension in advanced CKD

44
Q

what are the main uses of thiazides?

A

hypertension

45
Q

what are the main uses of amiloride?

A

low potassium where diuretic is required

46
Q

what is the main uses of aldosterone antagonists

A

heart failure
ascites
hypertension
hyperaldrenalism

47
Q

what are the main uses of ADH antagonist ?

A

hyponatraemia

48
Q

what are the main side effects of carbonic anhydrase inhibitors?

A

acidosis

renal stones

49
Q

what are the main side effects of osmotic diuresis?

A

allergic reactions

50
Q

what are the main side effects of loop diuretics ?

A 
alkalosis
metabolic effects ( increase urate and lipids )
51
Q

what is the main side effects of thiazides?

A

Electrolyte disturbance Metabolic effects (increased urate, glucose, lipids, impotence)

52
Q

what are the main side effects of amiloride?

A

hyperkalaemia

53
Q

what are the main side effects of aldosterone antagonists

A

hyperkalaemia

gynaecomastia

54
Q

what are the main side effects of ADH antagonists

A

hypernatraemia

Clinical Pharmacology (26 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions