Loop diuretics:
Mechanism:
Administration:
Examples:
Indications for Loop diuretics- like furosemide
Unwanted effects of loop diuretics
Dehydration
Hypokalemia
- potentiates the effects of cardiac glycosides.
Deafness- when used with aminoglycoside antibiotics
Osmotic diuretics:
Mechanism:
Example:
- Mannitol
Indications for osmotic diuretics [4]
Cerebral oedema
Reduces intracranial pressure in glaucoma
Elimination of toxins via osmotic diarrhea
Acute renal failure
Unwanted effects of osmotic diuretics
Increases plasma volume by exerting osmotic pressure
- Cannot be used for hypertension
Kaliuretics
Diuretics that promote K+ excretion.
Natriuretics
Diuretics that promote Na+ excretion.
Aquaretics
Diuretics that promote water excretion without Na+ excretion.
Carbonic anhydrase inhibitors:
Mechanism:
Example:
Acetazolamide [Diamox]
Carbonic anhydrase inhibitor indications
Reducing intraoccular pressure in glaucoma
Decrease volume and pressure of CSF in epilepsy.
Unwanted effects of carbonic anhydrase inhibitors
Metabolic acidosis
Increased production of renal stone
Potassium sparing diuretics:
Mechanism:
Examples:
Indications of K+ sparing diuretics
Heart failure
Oedema
Unwanted effects of K+ sparing diuretics
Hyperkalemia- does not increase secretion of K+
Metabolic acidosis
GI upsets
Gynaecomastia
Menstrual
Testicular atrophy
Amiloride and triamterene
Potassium sparing diuretics
Physically blocks apical Na+ channels instead of antagonising aldosterone like other K+ sparing drugs.
Combining diuretic agents
Used to:
Increases diuretic effects
Avoid hypokalemia
Thiazide diuretics:
Mechanism:
Examples:
Indications for thiazide diuretics
Hypertension
Oedema
Mild heart failure
Unwanted effects of thiazide diuretics [6]
Hypokalemia
Metabolic alkalosis:
Increase in Uric acid= gout
Hyperglycaemia due to increased Ca2+ absorption
Hypercholesterolemia
Male impotence
Thiazie-like diuretics
Like thiazide diuretics but with a different molecular structure.
- Inhibits Na+/Cl- co-transporter
Examples:
Xanthines
Chemical found in caffeine, theobromine, used as bronchodilator.
Acts as a weak diuretic- possible due to dilation of afferent arteriole.
ADH antagonists
Potential diuretics
- Prevents ADH making collecting duct impermeable to water, increasing aquaresis
Examples: Lithium Demeclocycline Amphotericin B Tolvaptan
These examples are either toxic or not that effective
Effectiveness of diuretics
Loop diuretics are the most effective:
Loop> Thiazide > Potassium sparing