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Flashcards in diuretics Deck (34)
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1
Q

where do loop diuretics act

A

TAL

2
Q

where do thiazide diuretics act

A

distal tubule

3
Q

where does spironolactone and amiloride act

A

collecting tubule

4
Q

what happens in the thick ascending loop

A

impermeable to water

active reabsorption of Na Cl

5
Q

what is the function of ADH

A

increases permeability to water of the collecting duct. this means more can be reabsorbed into the blood producing more concentrated urine

6
Q

what is the function of aldosterone

A

increases permeability of ions and water in the collecting duct

7
Q

how is sodium reabsorbed in the distal nephron

A

swapped for K and H ions

8
Q

how do diuretics work

A

cause naturesis which causes diuresis

9
Q

what is furosemide (loop diuretic)

A

loop diuretic.
inhibits absorption of ions in the TAL
they inhibit the counter current multiplier which sets up the concentration gradient
causes loss of K and H and increase in bicarbonate
increase renal prostaglandins which change renal blood flow

moderated in DCT which exchanges for sodium for K/H

very effective diuretic

10
Q

how do potassium sparing diuretics work. eg spironolactone

A

•Inhibits aldosterone-sensitive sodium pump by renal prostaglandin production

11
Q

how do carbonic anhydrase inhibitors work

A

inhibit transport of bicarbonate from the PCT into the interstitium leading to less sodium reasorbtion - very weak

12
Q

how are diuretics used in heart failure

A

decrease pre load which decreases blood pressure
decreases venous return
decreases oedema

13
Q

what are the symptoms of inappropriate ADH secretion

A
  • Nausea and/or vomiting
  • Cramps/tremors
  • Depressed mood, irritability, personality change, memory issues, hallucinations
  • Seizures
  • coma
14
Q

what are the causes of inappropriate ADH secretion

A
•CNS	– infections,	brain	tumour	or	bleed,	hydrocephalus,	Guillain-Barre,	MS
•Cancers	– Carcinomas	of	lung,	GIT,	GUT;	lymphomas;	sarcomas	
•Medication	– antibiotics
- some	anti	-epletics
- some	major	sedatives
- oxytocin
- MDMA	(	Ecstasy)
•Lung	disease
•Hypothyroidism	or	parathyroidism
•HIV
•Sarcoid
15
Q

how is inappropriate ADH secretion treated

A

fluid restriction
saline
tolvaptan

16
Q

what might polycythaemia be caused by

A

kidney tumour causing increase EPO production

17
Q

what is AZT for

A

anti retroviral therapy

18
Q

what hormones are produced in the adrenal cortex

A
  • Glucocorticoids e.g. cortisol
  • Mineralocorticoids e.g. aldosterone
  • Androgens
19
Q

what hormones are produced in the adrenal medulla (catecholamines)

A
  • adrenaline

* noradrenaline

20
Q

what is beclometasone

A

used to treat asthma, psoriasis, hayfever etc

steroid- glucocorticoid

21
Q

what is prednisolone used to treat

A

autoimmune and inflammatory disorders e.g. RA, asthma UC- glucocorticoid

22
Q

what is dexamethasone

A

glucocorticoid- anti inflammatory used in allergy and asthma

23
Q

what is fludrocortisone

A

mineralcorticoid-low blood pressure or to replace aldosterone
addison’s disease

24
Q

where is aldosterone produced

A

adrenal cortex

25
Q

why do loop diuretics cause metabolic alkalosis

A

lower plasma volume but same volume of bicarb. excretion of hydrogen ions

26
Q

what are the side effects of loop diuretics

A

risk of hypokalaemia and metabolic alkalosis

27
Q

where do thaizides act

A

DCT
inhibit sodium chloride transporter
used in hypertension

28
Q

where is carbonic anhydrase found

A

PCT

results in bicarb accumulation in the urine by inhibiting carbonic anhydrase which inhibits transport of bicarb

29
Q

what type of diuretic is aldosterone antagonist

A

potassium sparing e.g. spironolactone and eplerenone

they prevent sodium reabsorption by inhibiting the aldosterone sensitive sodium pump

30
Q

what is normal haematocrit

A

45%

31
Q

what is synthetic EPO used for

A

kidney failure pts
antiretroviral therapy pts
chemo and cancer pts

32
Q

describe the HPA axis (hypothalamus, anterior pituritary, adrenal cortex)

A

hypothalamus releases corticotropin releasing hormone to the anterior pituitary gland which signals to the adrenal gland using adrenocorticotropic hormone which releases cortisol from the adrenal cortex

33
Q

what are corticosteroids

A

reduce inflammation and suppress the immune system

34
Q

Where does aldosterone act

A

collecting duct

therefore spironolactone and eplenerone act here too (potassium sparing)