Les diurétiques

Question 1

What is a diuretic?

Answer 1

A substance that increases natriuresis… (the process of sodium excretion (salty water) in the urine through the action of the kidneys)

Better definition:

substance qui induit une balance sodée négative en inhibitant directement la réabsorption tubulaire de sodium

Question 2

What are the 4 sites where diuretics can work?

Answer 2

Tubule proximal

• Class?
  
  • Inhibiteurs de anhydrase carbonique, diurétiques osmotiques —> both not used anymore

Anse de Henle

• Class?
  
  • Diurétiques de l’anse

Tubule distal

• Class?
  
  • Diurétiques thiazidiques

Tubule collecteur

• Class?
  
  • Épargneurs de potassium

Question 3

What is the cible for diuretics in cellules tubulaires?

Answer 3

L’entrée de sodium du lumière tubulaire

Question 4

What do diuretics block in each location?

Answer 4

1. Proximal —> not important
2. Henle —> transporteur Na-K-2Cl (furosémide)
3. Distal —> co-transport NaCl (hydrochlorothiazide and chlorthalidone)
4. Collecteur —> block canal sodique (amiloride and triamtérène) OR block aldosterone from its receptor (spironolactone)
   
   • Spirnolactone is the only diuretic that works directly on the membrane basolatéral and not on the side of the lumière tubulaire

Question 5

How do diuretics work day by day?

Answer 5

Diuretic started on day 2… urine becomes very salty and water follows dropping her weight by 1.2kg day 3 —> VCE decreases which is perceived by baroreceptors which send a message to the renal tubules to reabsorb more sodium (in sites that aren’t blocked)… by day 5 a new equilibrium is found

Question 6

What is happens to your état d’équilibre when taking a diuretic?

Answer 6

Lors de la prise régulière d’un diurétique, on observe à l’état d’équilibre une excrétion sodée égale à l’ingestion, mais avec une contraction soutenue du liquide extracellulaire

Question 7

What are some indications for diuretics?

Answer 7

1. États d’oedème généralisé (coeur, foie, rein)
   
   • Diurétique de l’anse (furosémide)
2. Hypertension artérielle
   
   • Diurétique thiazidique (HCTZ), Chlorthalidone
3. Divers

Question 8

What are some possible combinations of diuretics? (3)

Answer 8

1. Thiazidique (III) + épargneurs de potassium (IV) —> additif (hypokalemie)
2. Anse (II) + épargneurs de potassium (IV) —> additif (hypokalemie)
3. Anse (II) + thiazidiques (III) —> synergique (increase diuretic effect)

Question 9

What are the 4 categories in which potential complications fall?

Answer 9

1. Hydroelectrolytic and acidobasic
2. Metabolic
3. Endocrine
4. Divers

Question 10

What are the 7 potential hydroelectrolytic/acidobasic complications?

Answer 10

Déplétion volémique (dim. VCE +++)

• Why?
  
  • Either dose too high of combined diuretics or too little salt in diet

L’azotémie

• Why?
  
  • État de contraction volémique

Hypokalemia: Metabolic alkalosis

• Why?
  
  • Tubule collecteur trop actif… secrete +++ K+ and H+ because inundated by flow

Hyperkalemia

Metabolic acidosis

• Why?
  
  • Tubule collecteur hypoactif… paralysé

Hyponatremia

• Why?
  
  • Secrete ADH to try to keep water in —> mécanisme d’urgence

Hypomagnesia —> not as important

Question 11

What are some examples of metabolic complications? (3)

Answer 11

Hyperuricémie (ureic acid)

Hyperlipidémie (cholesterol)

Hyperglycémie (insulin resistance)

Question 12

What are some examples of endocrine complications? (2)

Answer 12

Spironolactone is very similar to sex hormones

1. Gynecomastia
2. Menstrual irregularities

Question 13

What are some examples of “divers” complications? (2)

Answer 13

Ototoxicity —> Na-K-2Cl is in inner ears too so it can be inhibited by diuretics but VERY RARE (DIURÉTIQUES DE L’ANSE)

Others

Question 14

What are the determinants de la réponse diurétique? (5)

Answer 14

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