FUROSEMIDE

Question 1

Drug class

Answer 1

loop diuretic

Question 2

How does it work? (2)

Answer 2

1. they act on the ascending loop of Henle

2. here they inhibit the Na/K/Cl co-transporter

Question 3

What is Na/K/Cl co-transporter responsible for? (2)

Answer 3

1. responsible for transporting sodium, potassium and chloride ions from the tubular lumen into epithelial cell
2. water then follows by osmosis

Question 4

What does inhibiting the Na/K/Cl co-transporter? (2)

Answer 4

• prevents water going into the epithelial cells

- therefore water leaves the body

Question 5

In addition, what other effects does loop diuretics have on blood vessels?

Answer 5

1. blood vessels

- dilatation of veins

Question 6

How does furosemide work in acute heart failure? (2)

Answer 6

• reduces preload

- improves contractile function of the overstretched heart

Question 7

Indications (4)

Answer 7

1. lungs
   - acute pulmonary oedema
   - breathlessness
2. Heart
   - chronic heart failure
   - fluid overload
3. kidneys
   - renal disease
4. liver
   - liver failure

Question 8

Contra-indications (4)

Answer 8

1. hypovolemia or dehydration
2. hepatic encephalopathy
   - use with caution
3. severe hypokaelemia/ hyponaetremia
4. gout
   - may inhibit the excretion of uric acid

Question 9

Side effects (5)

Answer 9

1. dehydration
2. hypotension
3. increases urinary losses of sodium, potassium and chloride ions
4. increased excretion of magnesium, calcium, and hydrogen ions
5. ears
   - tinnitus
   - hearing loss

ASSOCIATE WITH ANY LOW ELECTROLYTE STATE

Question 10

Why does furosemide cause tinnitus and hearing loss?

Answer 10

as a similar Na/K/Cl co transporter regulates endolymph in the inner ear

Question 11

Interactions (3)

Answer 11

1. drugs that are excreted by the kidneys
   - lithium levels increase due to reduced excretion
2. digoxin

• toxicity increased
• due to diuretic related hypokaelemia

3. aminoglycosides
   - ototoxicity
   - nephrotoxicity

Question 12

Elimination (2)

Answer 12

• 88% kidneys

- 10-15% bilary