Digoxin Toxicity — RACP Adult Medicine MCQ

Instant feedback + full explanation. One question, done properly.

EasyCardiologyDigoxin ToxicityRACP Adult Medicine

A 75-year-old woman on digoxin 250 μg daily presents with nausea, visual disturbance (yellow-green halos), and bradycardia (HR 42 bpm). ECG shows atrial tachycardia with 2:1 block and scooped ST segments. Digoxin level is 3.8 nmol/L (therapeutic <2.6). K⁺ is 5.5 mmol/L. What is the most likely causative drug?

Educational content. Not a substitute for clinical judgement or local policy.

Reveal the answer and explanation

Correct answer: B — Digoxin

Digoxin toxicity presents with GI symptoms (nausea, vomiting), visual disturbance (xanthopsia — yellow-green halos), and cardiac arrhythmias. Atrial tachycardia with AV block is characteristic. Hypokalaemia potentiates toxicity (even at therapeutic levels), but here hyperkalaemia from AKI or acute toxicity is present. Treatment is digoxin-specific antibody fragments (Digifab).

Reference: AMH – 2025 – Digoxin; eTG Cardiovascular 2024