multi class comparison
IV Electrolyte Replacement: Potassium vs Magnesium vs Calcium — Rate, Route, Monitoring
Pushing IV potassium kills the patient. Pushing IV calcium too fast does the same. The NCLEX loves asking which electrolyte can never be given IV push and the safe infusion rates — one wrong answer choice and you've selected the lethal option.
Comparison
Side-by-side3 compared
Comparevs
Dimension
Potassium (K⁺)
Magnesium (Mg²⁺)
Calcium (Ca²⁺)
Class & mechanism
- KCl — restores intracellular cation
- MgSO₄ — cofactor, smooth-muscle relaxant
- Ca gluconate/chloride — restores Ca²⁺
Indications
- Hypokalemia
- Hypomagnesemia; torsades de pointes
- ★Preeclampsia/eclampsia seizure prophylaxis
- Hypocalcemia
- Cardioprotection in hyperkalemia
Route & administration
- IV diluted via pump; PO with food
- Central line if concentrated >10 mEq/hr
- IV infusion or IM; loading then maintenance
- IV slow push/infusion; central line preferred
Key assessment
- ECG: peaked T waves = hyperkalemia
- Deep tendon reflexes + respiratory rate
- Trousseau & Chvostek signs
Monitoring
- Continuous cardiac/ECG monitoring
- Verify serum level before & after
- Continuous cardiac/ECG monitoring
- Verify serum level before & after
- Continuous cardiac/ECG monitoring
- Verify serum level before & after
Adverse effects
- Phlebitis/burning at IV site
- Flushing, hypotension, drowsiness
- Bradycardia if pushed too rapidly
Toxicity / safety alert
- ★NEVER IV push — dilute & infuse via pump
- Toxicity: loss of DTRs, resp depression
- ★Antidote = IV calcium gluconate
- ★Extravasation → tissue necrosis
Contraindications & interactions
- Oliguria/renal failure; K-sparing diuretics
- Heart block; hold if DTRs absent
- Incompatible w/ many IVs — precipitates
Patient teaching
- Take oral dose with food; never crush ER
- Report weakness or trouble breathing
- Report numbness/tingling around mouth
Class & mechanism
Potassium (K⁺)
- KCl — restores intracellular cation
Magnesium (Mg²⁺)
- MgSO₄ — cofactor, smooth-muscle relaxant
Indications
Potassium (K⁺)
- Hypokalemia
Magnesium (Mg²⁺)
- Hypomagnesemia; torsades de pointes
- ★Preeclampsia/eclampsia seizure prophylaxis
Route & administration
Potassium (K⁺)
- IV diluted via pump; PO with food
- Central line if concentrated >10 mEq/hr
Magnesium (Mg²⁺)
- IV infusion or IM; loading then maintenance
Key assessment
Potassium (K⁺)
- ECG: peaked T waves = hyperkalemia
Magnesium (Mg²⁺)
- Deep tendon reflexes + respiratory rate
Monitoring
Potassium (K⁺)
- Continuous cardiac/ECG monitoring
- Verify serum level before & after
Magnesium (Mg²⁺)
- Continuous cardiac/ECG monitoring
- Verify serum level before & after
Adverse effects
Potassium (K⁺)
- Phlebitis/burning at IV site
Magnesium (Mg²⁺)
- Flushing, hypotension, drowsiness
Toxicity / safety alert
Potassium (K⁺)
- ★NEVER IV push — dilute & infuse via pump
Magnesium (Mg²⁺)
- Toxicity: loss of DTRs, resp depression
- ★Antidote = IV calcium gluconate
Contraindications & interactions
Potassium (K⁺)
- Oliguria/renal failure; K-sparing diuretics
Magnesium (Mg²⁺)
- Heart block; hold if DTRs absent
Patient teaching
Potassium (K⁺)
- Take oral dose with food; never crush ER
Magnesium (Mg²⁺)
- Report weakness or trouble breathing
★ marks the fact that sets a column apart.
Clinical Pearl
Potassium is NEVER pushed; magnesium toxicity is reversed by calcium; all three demand telemetry — slow is safe.
⚡ Speed Sort This Table
Swipe to sort 62 clinical items into the right bucket