Loop D

Question 1

what are the drugs in this class?

Answer 1

Furosemide and bumetanide

Question 2

what is the mechanism of action?

Answer 2

promote diuresis by inhibiting reabsorption (increase the excretion of sodium and water) from the ascending limb of the loop of henle in the renal tubule and are powerful diuretics.

they act 1 within 1 hour of oral administration and diuresis is complete within 6 hours. it is okay to give twice in one day as long as it doenst affect sleep and it isnt taken past 4pm.

Question 3

common indications

Answer 3

oedema
to relieve congestive symptoms and fluid retention in people with HF.
lower pulmonary oedema relieved breathlessness
doses are titrated up and down according to the response and need
diuresis is dependant on dose.

Question 4

cautions

Answer 4

severe hypokalemia
can exacerbate diabetes
before treatment initiation, hypotension and hypovalemia should be corrected
urinary retention (ensure urine excretion is sufficient)

Question 5

how does it promote hypokalemia?

Answer 5

This occurs because loop diuretics, such as furosemide, act on the loop of Henle in the nephron to inhibit the sodium-potassium-chloride co-transporter (NKCC2). This mechanism leads to increased excretion of sodium, potassium, and chloride in the urine

Question 6

when should loop diuretics not be used?

Answer 6

without evidence of heart failure, liver failure or nephortic syndrome.

Question 7

significant interactions of loop diuretics

Answer 7

antihypertensives
cardiac glycosides
lithium

Question 8

significant intercations with cardiac glycosides

Answer 8

LD increase risk of hypokalemia which increases the risk of digoxin toxicity.

Question 8

significant interaction of loop diuretic and antihypertensives

Answer 8

if given concomitantly with loop diuretics, enhanced hypotensive effects can be avoided with BP monitoring.

Question 8

significant interactions with lithium

Answer 8

LD decrease renal functions which reduces excretion of lithium, increasing risk of toxicity. LD increase risk of hyponotraemia, which increase risk of lithium toxicity.

Question 8

main side effects/adverse effects

Answer 8

dizziness, fatigue and headache
excessive diuretic
electrolyte imbalance
ototoxicity

Question 9

monitoring requirements

Answer 9

before starting treatment:
renal function
serum electrolytes
blood pressure
these should be remonitored 1-2 weeks after starting treatment and 1-2 weeks after each dose increase.

once treatment is stable, monitoring should be at least every 6 months. regular weight checks are required to assess the diuretic effect.