Diuretics Flashcards
Diuretics types?
- Carbonic Anhydrase Inhibitors
- Loop Diuretics
- Thiazide Diuretics
- Potassium Sparing Diuretics
- ADH Antagonists
Carbonic Anhydrase Inhibitor drugs?
Acetozolamide, Methozolamide,
Dorzolamide
Carbonic Anhydrase Inhibitors used for?
management of respiratory alkalosis,
urine alkalization for better excretion (eg. uric acid, cysteine),
glaucoma
Carbonic Anhydrase Inhibitors Mechanism of Action?
• Inhibition of carbonic anhydrase
- ↓ HCO3- reabsorption, ↓ Na+ reabsorption (charge
balance) , ↓ water retention
• Limited effectiveness over time as HCO3- stores are depleted
and metabolic acidosis sets in
Carbonic Anhydrase Inhibitors Side Effects & Contraindications?
• Metabolic acidosis • GIT disturbances • Peripheral tingling and numbness • Possible hepatic effects (avoid in cirrhotic patients)
Loop Diuretics drugs?
Furosemide (sulphonamide), Etacrynic
acid
Loop Diuretics Mechanism of Action?
• Inhibition of NKCC2
- ↓ Na+ & Cl- reabsorption, ↓ water retention
- ↓ Ca2+ & Mg2+ reabsorption (charge balance)
- Highest ceiling due to large reabsorptive potential and no dose ceiling
Loop Diuretics Side Effects & Contraindications?
- Hypokalemia, Hypokalemic metabolic alkalosis
- Hyperuricemia
- Hypomagnesemia, Hypocalcemia
- Ototoxicity (avoid vancomycin, aminoglycosides)
- Allergic reaction (sulphur present)
Loop Diuretics used for?
First choice drug for management of acute
heart failure and associated oedema
Thiazide Diuretics drugs?
Hydrochlorothiazide
Thiazide Diuretics Mechanism of Action?
• Inhibition of Na+/Cl- cotransporter
- ↓ Na+ & Cl- reabsorption, ↓ water retention
- ↑ Ca2+ reabsorption
Thiazide Diuretics Side Effects & Contraindications?
- Hypokalemia
- Hypochloremic metabolic alkalosis
- Hyperuricemia
- Hypercalcemia – can unmask underlying pathology
- Allergic reaction (sulphur present)
Potassium Sparing Diuretics drugs?
– Steroid: Spironolactone, Eplerenone
– Non-steroidal: Amiloride, Triamterene
Potassium Sparing Diuretics used for?
hypokalemic metabolic alkalosis
Potassium Sparing Diuretics Mechanism of Action?
Steroidal:
- Direct antagonism of aldosterone leading to decreased Na+ reabsorption while increasing K+ uptake.
- Relative slow onset of action.
Non-steroidal: Inhibition of ENaC Na+ reabsorption
