Digoxin

Question 1

Name 5 risk factors for digoxin toxicity

Answer 1

Elderly
Hypokalaemia
Hypercalcaemia
Hypomagnesaemia
Alkalosis
Hypoxia
Hypothyroidism
Renal impairment

Question 2

Name 3 biochemical risk factors for digoxin toxicity?

Answer 2

Hypokalaemia
Hypercalcaemia
Hypomagnesaemia

Question 3

What is the antidote for digoxin toxicity?

Answer 3

Digoxin-specific antibody

Question 4

What are the SSx of digoxin toxicity?

Answer 4

Blurred vision (yellow-green vision)
Nausea and vomiting
Confusion
Arrhythmias

Question 5

How soon after the dose of digoxin do you measure its concentration?

Answer 5

6 hours later

Question 6

When would you consider prescribing a lower dose of digoxin?

Answer 6

Thyroid disease i.e thyrotoxicosis
Renal impairment
Older age
Electrolyte imbalances
Concurrent prescription with amiodarone/quinine

Question 7

How much do you have to increase the dose by when switching from IV digoxin to PO digoxin

Answer 7

Increase dose by 20–33% to maintain the same plasma-digoxin concentration

This is because of reduced bioavailability of oral compared to IV

Question 8

What patient parameters do you have to measure for a patient on digoxin?

Answer 8

eGFR

U + E

Question 9

Give 4 ECG features of digoxin toxicity?

Answer 9

Multifocal atrial tachycardia
ST depression
Shortened QT interval
Flattened T wave