Diuretics

Question 1

What is the mechanism of action of loop diuretics? How does it remove fluid?

Answer 1

• inhibit the Na+/K+/2Cl co-transporter in the thick ascending limb of the loop of Henle,
• increasing the excretion of sodium, chloride, and potassium (and some magnesium) leading to increased urine output.

Question 2

What are common uses of loop diuretics?

Answer 2

Fluid overload due to heart failure, liver disease, or kidney disease, and to manage high blood pressure

Question 3

Name 2 common loop diuretics.

Answer 3

Furosemide (Lasix), bumetanide (Bumex), torsemide (Demadex), and ethacrynic acid (Edecrin).

Question 4

What are 5 potential side effects of loop diuretics?

Answer 4

• Electrolyte imbalances (low potassium, low sodium, low magnesium),
• Dizziness
• Fatigue, headache, nausea
• Metabolic acidosis
• Dehydration, postural hypotension, dizziness, confusion, AKI if in excess

These are common

https://bnf.nice.org.uk/drugs/furosemide/#side-effects

Question 5

If people taking diuretic develop diarrhoea and vomiting while taking a diuretic, what should they do?

Answer 5

Maintain their fluid intake and stop the diuretic for 1–2 days until they recover.

Question 6

A patient starts taking diuretics for acute heart failure. They start experiencing muscle spasms/cramps, weakness, headache, and palpitations. What might be the causes

Answer 6

Electrolyte imbalances e.g. hypokalaemia, hypomagnesemia, hyponatraemia

Question 7

Which electrolytes do diuretics affect?

Answer 7

• Sodium
• Potassium
• Magnesium
• Chloride

Question 8

Why might a patient on loop diuretics develop metabolic alkalosis?

Answer 8

Loss of chloride ions and increase in H+ ions (in response to hypokalaemia) causes retention of bicarbonate.

Question 9

Which metabolic product is retained during the use of diuretics? What might it trigger?

Answer 9

Uric acid. Gout