Diuretics Flashcards
What is a diuretic drug?
Increase production of urine
What is a natriuretic drug?
Loss of sodium in urine
What is a aquaretic drug?
Loss of water without electrolytes
Uses of diuretics
- Primary hypertension
- Chronic heart failure
- Nephrotic syndrome
- CKD
- oedema
Common adverse effects of diuretics
- hypovolaemia + hypotension
- electrolyte disturbance
- metabolic abnormalities
- anaphylaxis
- photo sensitive rash
Where do thiazide + thiazide like diuretics work?
DCT
Examples of thiazide + thiazide like diuretics
Bendroflumethiazide
Indapamide
How do thiazide + thiazide like diuretics work?
- in DCT
- inhibit Na/Cl co transporter
- Na+/Cl- remain in nephron
- H2O follows
Adverse effects of thiazide + thiazide like diuretics
- gout
- hyperglycaemia
- erectile dysfunction
- hypercalcaemia
- hypokalaemia
Contraindications of thiazide + thiazide like diuretics
- Addison disease
- gout
- hypercalcaemia
- Hyponatraemia
- symptomatic hyperuricaemia
Important drug interactions of thiazide + thiazide like diuretics
Alcohol
Amlodipine
Loop diuretics - also K+ wasting
How do loop diuretics work?
- in loop of henle
- inhibit NKCC co transporter
- reduced Na,K,Cl into epithelium
- H2O follows
How can thiazide + thiazide like diuretics cause hypokalaemia?
- 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
Adverse effects of loop diuretics
- dehydration
- hypotension
- hypokalaemia
- Hyponatraemia
- gout
- arrhythmia
- tinnitus
Why can loop diuretics be used for hearty failure?
Cause direct dilatation of capacitance veins > reduces preload
Contraindications of loop diuretics
Hypokalaemia
Hyponatraemia
Gout
Hepatic encephalopathy
Important drug interactions of loop diuretics
Aminoglycosides
Digoxin
Lithium
Examples of loop diuretics
Bumetanide
Furosemide
How does amiloride work?
What type of drug is it?
- 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
How does spironolactone work?
What type of drug is it?
- in collection duct/late DCT
- aldosterone antagonist
- potassium sparing antagonist
- less aldosterone > less ENaC > less Na+ reabsorption
- less K+ excretion through ROMK
Adverse effects of amiloride
Hyperkalaemia
Arrhythmias
Contraindications of amilorde
Addison’s disease
Anuria
Hyperkalaemia
Important drug interactions of amiloride
Other K+ sparing drugs
ACEi
ARBs
Examples of aldosterone antagonists
Spironolactone
Adverse effects of aldosterone antagonist
Hyperkalaemia
Severe cutaneous adverse reactions
Gynaecomastia
What is gynaecomastia?
Enlargement of man’s breast
(‘Man boobs’)
What drinks cause diuresis?
How?
Alcohol: inhibits ADH release
Caffeine: ^ GFR + v tubular Na+ reabsorption
