Digoxin Toxicity NCLEX Priority Sheet

NCLEX memory rule: anorexia is the classic earliest sign, followed by nausea and vomiting.

Visual: yellow-green halos, blurred vision, photophobia.

Cardiac: bradycardia, PVCs, heart block, or new arrhythmias.

Neuro: confusion, weakness, dizziness.

Early vs. late: GI symptoms appear first; cardiac and neurologic signs indicate worsening toxicity.

Trap: a patient on digoxin has K+ 3.2 mEq/L.

Safer answer: recognize hypokalemia as a major digoxin toxicity risk, notify the provider, and anticipate potassium correction as ordered. Low K+ increases myocardial sensitivity to digoxin, so toxicity can occur even at a therapeutic digoxin level.

Digoxin is a positive inotrope. It increases myocardial contractility by inhibiting the Na+/K+-ATPase pump, which raises intracellular calcium and strengthens the force of contraction.

Clinically, digoxin also has a negative chronotropic effect: it slows the heart rate by increasing vagal tone and slowing conduction through the AV node. NCLEX often tests this distinction.

Do not confuse inotropic (force of contraction) with chronotropic (rate of contraction).

Hold and notify the provider per protocol when you see:

- Apical pulse below 60 bpm in adults (or per ordered parameter)
- New visual changes such as yellow-green halos or blurred vision
- New arrhythmias, heart block, or bradycardia
- Confusion, severe weakness, or suspected toxicity
- Hypokalemia or a falling potassium level that increases toxicity risk

Follow the ordered patient-specific parameters rather than treating one number as a universal rule. See the dedicated When to Hold Digoxin Priority Sheet for the full exam-focused pattern.

Common NCLEX pairing: digoxin + furosemide.

Loop diuretics can lower potassium. Hypokalemia increases digoxin toxicity risk. When these drugs appear together, look for potassium level, apical pulse, GI symptoms, visual changes, and renal function.

Question: A patient taking digoxin reports yellow halos and has an apical pulse of 56. What should the nurse do first?

Answer: hold the dose per institutional protocol, assess for toxicity, and notify the provider. Visual disturbance plus bradycardia is a classic digoxin toxicity pattern.

Saunders Comprehensive Review for the NCLEX-RN Examination; Davis's Drug Guide for Nurses; 2022 ACC/AHA/HFSA Guideline for the Management of Heart Failure.