Diuretics

Question 1

Loop Diuretics

Answer 1

Fruosemide

Most powerful
Block NK2Cl in acending LOH
causes loss of Na, K, Cl, Ca, Mg
loss of water

Treat oedema, heart failure
can cause hypokalemia and hypotension

Question 2

Thiazides

Answer 2

Thiazides

Block Na/Cl transporter in DCT - increase Na, Cl and water excretion

Indications: hypertension, oedema

SE: Hypokalaemia, Hyponatraemia, Hypercalcaemia
Reduced glucose tolerance

• fast onset
• NSAIDs reduce efficacy

Preferred in treating hypertension as activation of RAS prevents hypotension
synergistic with loop
less Ca loss - pref for osteoporosis

Question 3

Aldosterone Antagonists

Answer 3

can also be called k sparing
eg. Spironolactone

Compete for intracellular receptor in DCT
Causes increased Na and decreased K in urine

Antihypertensive but can cause hyperkalemia

Question 4

K sparing

Answer 4

Amiloride
Act on collecting ducts
Block ENaC channel and decrease K excretion
can cause hyperkalemia

Question 5

Carbonic Anhydrase

Answer 5

eg. ace tazo lamide
Act on PCT
Inhibition of reabsorption of Na and HCO3
causes alkaline urine can cause metabolic acidosis

Question 6

Osmotic Diuretics

Answer 6

eg. Mannitol
Modify the content of filtrate
Pharmacologically inert substances that are filtered but not reabsorbed - prevent H20 being reabsorbed

Treatment of high ICP

Question 7

Name three inappropriate uses of diuretics

Answer 7

Weight loss
Oedema of pregnancy
Premenstrual tension