NCLEX-RNPhysiological AdaptationEasy
A client taking digoxin and furosemide reports nausea and seeing yellow-green halos around lights. The morning laboratory results show potassium 3.0 mEq/L, sodium 138 mEq/L, and magnesium 1.9 mEq/L. Which action should the nurse take first?
- AAdminister the scheduled dose of digoxin
- BRecheck the magnesium level in 4 hours
- CHold the digoxin dose and notify the provider
- DAdminister intravenous potassium chloride by IV push
Show answer & explanationAnswer & explanation
Correct answer: C. Hold the digoxin dose and notify the provider
Hypokalemia increases myocardial sensitivity to digoxin, precipitating toxicity even at therapeutic digoxin levels. Visual disturbances and nausea are classic toxicity signs, so the nurse should hold the drug and notify the provider rather than administer another dose.
Why the other options are wrong
- A. Giving digoxin with these symptoms and low potassium risks worsening toxicity and dysrhythmias.
- B. Rechecking magnesium delays urgent intervention for active toxicity symptoms.
- D. IV push potassium is never given due to risk of fatal cardiac arrhythmia; it must be diluted and infused slowly.
Digoxin Toxicity & Hypokalemia
Low serum potassium increases digoxin binding to cardiac cells, potentiating toxic effects even at normal digoxin levels.
- Signs: nausea, visual halos, bradycardia, dysrhythmias
- Never give IV potassium by push—infuse slowly and diluted
- Loop diuretics like furosemide cause potassium loss increasing toxicity risk
Memory trick: Low K = digoxin gets stronger and more toxic