Digoxin Flashcards
(14 cards)
What is the typical loading dose of digoxin?
250–750 micrograms a day for 7 days. For rapid digitalisation: 750 micrograms to 1.5 mg in divided doses over 24 hours.
What is the typical maintenance dose of digoxin?
125–250 micrograms daily, adjusted according to renal function and clinical response.
How often should serum electrolytes and renal function be monitored in people taking digoxin?
At least annually; more frequently in the elderly or those with renal impairment.
When should plasma digoxin levels be checked?
Only if clinically indicated, such as:
Suspected toxicity
Renal impairment
Thyroid disease
Drug interactions
Poor adherence
When should digoxin blood samples be taken if levels are checked?
At least 6 hours after the last dose.
What digoxin levels indicate possible or likely toxicity?
1.5–3 micrograms/L: toxicity possible
3 micrograms/L: toxicity likely
What are signs of digoxin toxicity?
Confusion, nausea, vomiting, anorexia, dizziness, palpitations, colour vision disturbances.
What are the absolute contraindications to digoxin use?
Supraventricular arrhythmias with accessory pathways (e.g. WPW)
Intermittent complete heart block or second-degree AV block
Myocarditis
Ventricular tachycardia or fibrillation
In which conditions should digoxin be used with caution?
Constrictive pericarditis
Hypertrophic cardiomyopathy
Recent MI
Sick sinus syndrome
Thyroid disease
Severe respiratory disease
Electrolyte imbalances
Renal impairment
Elderly
What are common adverse effects of digoxin?
Arrhythmias, nausea, vomiting, dizziness, vision disturbances, diarrhoea, and cardiac conduction disorders.
Name three drugs that increase digoxin concentration.
Amiodarone
Verapamil
Clarithromycin
Name three drugs that reduce digoxin absorption or concentration.
Antacids
Rifampicin
St John’s Wort
Why must caution be used when prescribing digoxin with diuretics?
Diuretics may cause electrolyte disturbances, increasing the risk of digoxin toxicity.
Which electrolytes must be monitored to prevent digoxin toxicity?
Potassium, magnesium, and calcium.
