Loop Diuretics

Question 1

What is indicated for?

Answer 1

Acute pulmonary oedema- for relief breathlessness
Chronic heart failure
Treatment of fluid overload in other oedematous states

Question 2

What is it mechanism of action?

Answer 2

They inhibit Na+/K+/2Cl− co-transporter, a protein responsible for transporting sodium, potassium and chloride ions from tubular lumen into the epithelial. Causing a potent diuretic effect.

Question 3

What are the side effects?

Answer 3

Water loss can cause dehydration and hypotension
Hyponatraemia or Hypernatremia
Hypokalaemia
Hypochloraemia
Hypocalcaemia
Hypomagnesaemia
Metabolic alkalosis
Hearing loss and tinnitus

Question 4

What are the warnings of this drug class?

Answer 4

Contraindicated in severe hypovolemia, dehydration
Caution in hypokalaemia and hyponatraemia and in patients at risk of hepatic encephalopathy
They inhibit uric acid excretion worsening gout

Question 5

What are the interactions of this class?

Answer 5

Drugs that are excreted by the kidneys- lithium
Digoxin toxicity due to diuretic-associated hypokalaemia
Loop diuretics can increase the ototoxicity and nephrotoxicity of aminoglycosides.

Question 6

What are the names of drugs in this class?

Answer 6

Furosemide
Bumetanide