Nursing care
Digoxin Toxicity: what to check before you give it
Written and reviewed by Dana Whitfield, RN, MSN · 5 min read · Updated September 2026
Short answer
Digoxin toxicity nursing care starts before the dose is given: check the apical pulse for a full minute and hold for a rate under 60, and check the potassium level, since hypokalaemia makes toxicity worse even when the digoxin level itself is normal. Early signs are gastrointestinal, anorexia and nausea, before visual changes like yellow-green halos appear.
What it does and why it is prescribed
Digoxin inhibits the sodium-potassium ATPase pump in cardiac cells, which increases intracellular calcium and produces a positive inotropic effect, a stronger contraction with each beat. It also slows conduction through the AV node, giving it a negative chronotropic effect that is useful for rate control.
Clinically it is used in heart failure with reduced ejection fraction to improve contractility and symptoms, and in atrial fibrillation or atrial flutter to slow ventricular response. It has a narrow therapeutic index, meaning the gap between an effective dose and a toxic one is small, which is why monitoring is built into every aspect of its use rather than being an afterthought.
Nursing considerations before giving it
Take an apical pulse for a full 60 seconds before every dose, not a radial pulse and not a partial count. Hold the dose and notify the prescriber if the rate is below 60 beats per minute in an adult, since digoxin's negative chronotropic effect can push an already slow rate into symptomatic bradycardia.
Check the most recent potassium level before administering. Hypokalaemia increases myocardial sensitivity to digoxin, so a patient can show signs of toxicity at a digoxin level that would otherwise be considered therapeutic. This is the detail worth holding onto: a normal digoxin level does not rule out toxicity if the potassium is low. Also review renal function, since digoxin is renally cleared and reduced clearance raises serum levels even without a dose change.
What to monitor
Monitor serum digoxin level, with a therapeutic range generally cited around 0.5 to 2.0 ng/mL, though the target used clinically is often narrower and should be confirmed against the ordering facility's reference range. Monitor serum potassium, magnesium and calcium, since all three electrolytes affect cardiac excitability and digoxin's action together.
Track apical pulse and rhythm continuously if the patient is on telemetry, or at minimum before each dose. Watch renal function trends, particularly in older adults and anyone on diuretics, since dehydration or declining renal clearance can push a stable patient into toxicity without any change to the prescribed dose.
Side effects versus adverse effects
Expected side effects at therapeutic dosing are usually mild and may include some gastrointestinal upset, but persistent or worsening gastrointestinal symptoms are actually an early warning sign rather than something to dismiss as routine. Anorexia and nausea are frequently the first indicators that a patient is trending toward toxicity, often appearing before any cardiac symptom is documented.
Adverse, toxic effects extend beyond the gut: visual disturbances including blurred vision, halos, and a distinctive yellow-green tint to vision; confusion, especially in older adults; and cardiac dysrhythmias, which are the most dangerous consequence and can range from bradycardia and heart block to ventricular ectopy. Any patient reporting new visual changes alongside anorexia and nausea should be treated as a toxicity concern until proven otherwise.
What to hold for and when to call
Hold the dose and call the prescriber for an apical pulse below 60, a potassium level outside the normal range in either direction, a digoxin level above the therapeutic range, or any new dysrhythmia on the monitor. Also hold and escalate if the patient reports new visual disturbance, confusion, or gastrointestinal symptoms that are worsening rather than incidental.
Because hypokalaemia potentiates toxicity, a patient on digoxin who is also on a potassium-wasting diuretic like furosemide needs particularly close potassium monitoring; correcting a low potassium can resolve apparent toxicity without the digoxin dose ever needing adjustment. In confirmed severe toxicity, digoxin immune Fab is the antidote and reverses life-threatening dysrhythmias by binding free digoxin.
Patient teaching
Teach the patient to check their own pulse before taking each dose and to withhold the dose and contact their provider if it falls below 60, or whatever threshold the prescriber has specified. Explain that the dose should never be doubled to make up for a missed one.
Tell the patient to report anorexia, nausea, vomiting, visual changes including seeing halos around lights or a yellow-green tinge to vision, palpitations, or confusion promptly rather than waiting for a scheduled appointment. Reinforce the importance of routine blood tests for both digoxin level and potassium, and advise the patient to mention digoxin use to any other prescriber, since several common drugs, including some diuretics and antiarrhythmics, alter digoxin levels or the potassium that governs its safety.
The next step on this is the same as on everything else here: answer questions and read the rationales. Our cardiovascular practice questions are the closest set to what this page covers.
Common questions
Why do you take an apical pulse instead of a radial pulse before giving digoxin?
The apical pulse reflects the actual heart rate directly, including irregular beats a radial pulse can miss. Digoxin slows AV conduction, so an accurate central measurement is needed to catch bradycardia before the dose is given.
Can digoxin toxicity happen at a normal digoxin level?
Yes. Hypokalaemia increases the heart's sensitivity to digoxin, so a patient can show toxic signs at a digoxin level within the therapeutic range if their potassium is low. Always check potassium alongside the digoxin level when toxicity is suspected.
What is the earliest sign of digoxin toxicity to watch for?
Gastrointestinal symptoms, particularly anorexia and nausea, typically appear before cardiac or visual signs. Persistent or new-onset nausea in a patient on digoxin should prompt a level check rather than being treated as routine.
What is the antidote for digoxin toxicity?
Digoxin immune Fab (Digibind or DigiFab) binds free digoxin and is used for severe, life-threatening toxicity with dangerous dysrhythmias. It is reserved for confirmed serious toxicity, not for mild gastrointestinal symptoms alone.
What heart rate means I should hold digoxin?
Hold the dose for an apical pulse below 60 beats per minute in an adult and notify the prescriber. Facility protocols may specify a different threshold for paediatric patients, so confirm against local policy.
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