Diuretics

Question 1

What is a diuretic drug?

Answer 1

Increase production of urine

Question 2

What is a natriuretic drug?

Answer 2

Loss of sodium in urine

Question 3

What is a aquaretic drug?

Answer 3

Loss of water without electrolytes

Question 4

Uses of diuretics

Answer 4

• Primary hypertension
• Chronic heart failure
• Nephrotic syndrome
• CKD
• oedema

Question 5

Common adverse effects of diuretics

Answer 5

• hypovolaemia + hypotension
• electrolyte disturbance
• metabolic abnormalities
• anaphylaxis
• photo sensitive rash

Question 6

Where do thiazide + thiazide like diuretics work?

Answer 6

DCT

Question 7

Examples of thiazide + thiazide like diuretics

Answer 7

Bendroflumethiazide
Indapamide

Question 8

How do thiazide + thiazide like diuretics work?

Answer 8

• in DCT
• inhibit Na/Cl co transporter
• Na+/Cl- remain in nephron
• H2O follows

Question 9

Adverse effects of thiazide + thiazide like diuretics

Answer 9

• gout
• hyperglycaemia
• erectile dysfunction
• hypercalcaemia
• hypokalaemia

Question 10

Contraindications of thiazide + thiazide like diuretics

Answer 10

• Addison disease
• gout
• hypercalcaemia
• Hyponatraemia
• symptomatic hyperuricaemia

Question 11

Important drug interactions of thiazide + thiazide like diuretics

Answer 11

Alcohol
Amlodipine
Loop diuretics - also K+ wasting

Question 12

How do loop diuretics work?

Answer 12

• in loop of henle
• inhibit NKCC co transporter
• reduced Na,K,Cl into epithelium
• H2O follows

Question 13

How can thiazide + thiazide like diuretics cause hypokalaemia?

Answer 13

• inhibition of Na/Cl co transport in DCT
• Na+ in nephron
• at collecting duct, Na+ reabsorbed by ENaC
• K+ moves into nephron via ROMK
• hypokalaemia

Question 14

Adverse effects of loop diuretics

Answer 14

• dehydration
• hypotension
• hypokalaemia
• Hyponatraemia
• gout
• arrhythmia
• tinnitus

Question 15

Why can loop diuretics be used for hearty failure?

Answer 15

Cause direct dilatation of capacitance veins > reduces preload

Question 16

Contraindications of loop diuretics

Answer 16

Hypokalaemia
Hyponatraemia
Gout
Hepatic encephalopathy

Question 17

Important drug interactions of loop diuretics

Answer 17

Aminoglycosides
Digoxin
Lithium

Question 18

Examples of loop diuretics

Answer 18

Bumetanide
Furosemide

Question 19

How does amiloride work?
What type of drug is it?

Answer 19

• in collecting duct/late DCT
• block ENaC channels
• reduces Na+ reabsorption in DCT
• reduced K+ excretion via ROMK
• often used with loop or thiazide diuretics to limit K+
  .
• potassium sparing drug

Question 20

How does spironolactone work?
What type of drug is it?

Answer 20

• in collection duct/late DCT
• aldosterone antagonist
• potassium sparing antagonist
• less aldosterone > less ENaC > less Na+ reabsorption
• less K+ excretion through ROMK

Question 21

Adverse effects of amiloride

Answer 21

Hyperkalaemia
Arrhythmias

Question 22

Contraindications of amilorde

Answer 22

Addison’s disease
Anuria
Hyperkalaemia

Question 23

Important drug interactions of amiloride

Answer 23

Other K+ sparing drugs
ACEi
ARBs

Question 24

Examples of aldosterone antagonists

Answer 24

Spironolactone

Question 25

Adverse effects of aldosterone antagonist

Answer 25

Hyperkalaemia
Severe cutaneous adverse reactions
Gynaecomastia

Question 26

What is gynaecomastia?

Answer 26

Enlargement of man’s breast
(‘Man boobs’)

Question 27

What drinks cause diuresis?
How?

Answer 27

Alcohol: inhibits ADH release
Caffeine: ^ GFR + v tubular Na+ reabsorption