LOOP DIURETICS

Question 1

Indications

Answer 1

• Pulmonary oedema (due to left ventricular failure)
• Chronic heart failure
• Hypertension

Question 2

Examples

Answer 2

• Furosemide
• Bumetanide

Question 3

Onset of action

Answer 3

• within 1 hour of oral administration and diuresis is completed within 6 hours
• If necessary they can be given twice a day without interfering with sleep

Question 4

Administration

Answer 4

• morning
• to prevent inteference with sleep

Question 5

SE

Answer 5

• Gout
• Hyperglycaemia
• Hypokalaemia
• Hyponatraemia
• Hypocalcaemia
• Postural hypotension
• tinnitus, and deafness (ototox)

Question 6

What is the difference between thiazide-related and loop diuretics in terms of electrolyte disturbances?

Answer 6

1. Hypokalaemia
2. Hyponatraemia)
3. Difference in Calcium levels
   - Thiazide-like diuretics increase calcium (Hypercalcaemia)
   - Loop diuretics decrease calcium (Hypocalcaemia)

Question 7

When is tinnitus and deafness as a side effect likely with loop diuretics?

Answer 7

In renal impairment
Especially if high doses are given

Question 8

Can Loop diuretics be used in renal impairment?

Answer 8

• High doses of loop diuretics may occasionally be needed in renal impairment
• It can be used in renal impairment
• Note side effects are more likely

Question 9

Monitoring
requirements for loop diuretics?

Answer 9

Monitor electrolytes (especially potassium) during treatment

Question 10

Interactions

Answer 10

1. AMINOGLYCOSIDES - Loop diuretics can increase ototoxicity and nephrotoxicity
2. LITHIUM - Loop diuretics increase the
   concentration of lithium
3. DIGOXIN - Risk of digoxin toxicity may also be increased
4. NSAIDS - the risk of nephrotoxicity/AKI and effectiveness of diuretic may be reduced
5. Other drugs that lower potassium (e.g. Thiazide-related diuretics diuretics)
6. Other antihypertensive drugs - Hypotension