Cardiac Glycoside Pregnancy: Use with caution; crosses placenta; monitor fetal heart rate

Digoxin

Brand names: Lanoxin

Adult dose

Dose: 62.5-250 micrograms once daily

Route: Oral

Frequency: Once daily

Max: 250 micrograms/day (standard); higher doses rarely justified

Loading dose: 0.5-1 mg IV/oral in divided doses. Maintenance depends on renal function and serum levels

Paediatric dose

Dose: Seek specialist opinion N/A/kg

Route: Oral

Frequency: Seek specialist opinion

Max: Seek specialist opinion

Seek specialist opinion

Dose adjustments

Renal

Significant reduction required — renally excreted; eGFR 10-50: reduce dose by 25-50%; eGFR under 10: use 62.5 micrograms every 48 hours; check levels

Hepatic

No adjustment required (not hepatically metabolised)

Paediatric weight-based calculator

Patient weight (kg)

Seek specialist opinion

Clinical pearls

Narrow therapeutic index: target serum level 0.5-0.9 nanomol/L (rate control in AF) — toxicity more likely above 2 nanomol/L
Toxicity triad in elderly: GI symptoms + bradycardia/arrhythmia + CNS effects (confusion, visual changes) — check level urgently
STOPP criteria: avoid digoxin as first-line rate control in AF if eGFR under 30 — accumulation risk
Hypokalaemia (e.g. from loop diuretics) potentiates toxicity — always monitor electrolytes
Antidote: Digibind (digoxin-specific antibody fragments) for life-threatening toxicity

Contraindications

Ventricular fibrillation
Hypertrophic obstructive cardiomyopathy
Wolff-Parkinson-White syndrome (accessory pathway conduction)
Intermittent complete heart block

Side effects

Nausea and vomiting (early toxicity signs)
Bradycardia and heart block
Visual disturbances (yellow-green tinge, halos — classic toxicity)
Confusion and delirium (elderly)
Arrhythmias (PAT with block, VT)
Hypokalaemia dramatically increases toxicity risk

Interactions

Amiodarone (doubles digoxin levels — halve digoxin dose)
Verapamil / diltiazem (increase digoxin levels, additive bradycardia)
Loop diuretics / thiazides (hypokalaemia increases toxicity)
Macrolide antibiotics (increase levels via P-glycoprotein inhibition)
Colestyramine (reduces absorption)

Monitoring

Serum digoxin level (6-8 hours post-dose)
U&E and eGFR
ECG (PR prolongation, ST changes)
Heart rate

Reference: BNFc; BNF 90; NICE NG106 (Chronic Heart Failure); ESC AF Guidelines 2020; STOPP/START v3. Verify against your local formulary and the latest BNF before prescribing.

Curated clinical cross-links plus same-class fallbacks.

Calculators

Pathways