Diuretics Flashcards
What is a diuretic?
Any drug that increases the water/solute excretion
What is the action of diuretics in the kidney?
Either altered systemic physiology
Or direct action
What are osmotic diuretics and how do they work?
Eg mannitol
They are filtered by the glomerulus but are not readily reabsorbed
This increases the osmolarity of tubular fluid
Decreases water reuptake
What are osmotic diuretics used for therapeutically?
Acute glaucoma
Cerebral oedema
Oliguria
What are direct drug effects?
Action on tubule reabsorption processes
Secreted into proximal tubule
Plasma protein bound
What are loop diuretics?
Affect mechanism of uptake in the loop of Henle
How are loop diuretics administered?
Orally
Intravenously
What are the side effects of loop diuretics?
Dehydration Mg2+, Ca2+, H+ and K+ excretion increases Alkalosis Hypokalaemia Deafness
What are the therapeutic uses of loop diuretics?
Heart failure Pulmonary oedoma Renal failure Hypercalcaemia/kalaemia Hyper tension Drug overdose
Where do thiazides work?
In the distal convoluted tubule
How are thiazides administered?
Orally
Side effects of thiazides
Mg2+ H+ and K+ excretion is increased
Calcium excretion decreases
Kidney stones
Erectile dysfunction
What are thiazides?
Drugs that effect the distal convoluted tubule
What are therpaeutic uses of thiazides?
Hypertension
Decreasing blood volume and hypertension
Heart failure and oedema
What are potassium-sparing diuretics?
Mineralcorticoid receptor agonists that inhibit aldosterone action and affect the DCT and collecting ducts
