Digoxin

Question 1

What is the therapeutic range for Digoxin?

Answer 1

0.8 to 2 mcg/L

There are wide interindividual variations in this range.

Question 2

What may be required in the treatment with Digoxin?

Answer 2

Loading doses

This is often necessary to achieve the desired therapeutic effect.

Question 3

What serum electrolytes should be monitored during Digoxin therapy?

Answer 3

• K+
• Mg²+
• Ca²+

Electrolyte imbalance can potentiate toxicity.

Question 4

What is the major route of elimination for Digoxin?

Answer 4

Renal excretion

There is also hepatic metabolism to active metabolites.

Question 5

What are some warning signs of Digoxin toxicity?

Answer 5

• Arrhythmias
• Heart block
• Weakness
• Lethargy
• Dizziness
• Headache
• Mental confusion
• Psychosis
• Anorexia
• Nausea
• Vomiting
• Diarrhoea
• Abdominal pain
• Blurred vision
• Yellow vision

Patients should be aware of these symptoms.

Question 6

What actions should a patient take upon experiencing warning signs of Digoxin toxicity?

Answer 6

Report immediately to a doctor

Timely intervention is crucial.

Question 7

What is the bioavailability of intravenous Digoxin?

Answer 7

100%

This means that the entire dose enters systemic circulation.

Question 8

What is the bioavailability of Digoxin in tablet form?

Answer 8

50-90%

This requires dosage adjustments to maintain plasma concentration.

Question 9

List some drugs that can increase plasma concentration of Digoxin.

Answer 9

• Alprazolam
• Amiodarone
• Ciclosporin
• Itraconazole
• Lercanidipine
• Macrolides
• Mirabegron
• Nicardipine
• Nifedipine
• Quinine
• Spironolactone
• Verapamil

These interactions can lead to toxicity.

Question 10

What can reduce plasma concentrations of Digoxin?

Answer 10

St. John’s Wort

This herbal supplement is known to interact with various medications.

Question 11

Which medications can cause hypokalaemia and increase the risk of Digoxin toxicity?

Answer 11

• Acetazolamide
• Amphotericin
• Loop diuretics
• Thiazides

Hypokalaemia enhances the risk of cardiac toxicity.

Question 12

What types of drugs can impair renal function and affect plasma Digoxin concentration?

Answer 12

• NSAIDs
• ACE inhibitors

These drugs can complicate Digoxin therapy.

Question 13

What should be considered regarding dosage forms of Digoxin?

Answer 13

Different bioavailabilities

The dosage may need to be adjusted to maintain the same plasma-digoxin concentration.