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Electrolyte Supplement/Prescription

POTASSIUM CHLORIDE

POTASSIUM CHLORIDE

Clinical safety rating

caution

Comprehensive clinical and safety monograph for POTASSIUM CHLORIDE (POTASSIUM CHLORIDE).


Mechanism of Action

Potassium is the major intracellular cation. It is essential for the maintenance of intracellular tonicity, transmission of nerve impulses, contraction of cardiac, skeletal, and smooth muscle, and maintenance of normal renal function. Potassium chloride dissociates to provide potassium ions and chloride ions. Potassium repletion corrects hypokalemia and associated disorders.

What the body does with it

MetabolismPotassium is not metabolized; it is excreted primarily by the kidneys. Approximately 90% is excreted in the urine, with the remainder in feces and sweat. Renal excretion is influenced by aldosterone.
ExcretionPrimarily renal (90%) as potassium ion; minimal fecal (<10%) and sweat.
Half-lifeNot applicable; potassium is an electrolyte regulated by homeostasis, not classic elimination half-life. Under normal renal function, serum half-life of administered potassium is approximately 2-4 hours due to rapid cellular uptake and renal excretion.
Protein bindingMinimal; <2% bound to plasma proteins.
Volume of Distribution0.5-0.7 L/kg; distributes primarily to intracellular compartment (98% of total body potassium is intracellular).
BioavailabilityOral: 90-100% (well absorbed from gastrointestinal tract, subject to first-pass uptake by liver; bioavailability is near complete).
Onset of ActionIV: within seconds to minutes; oral: within 1-2 hours; depends on formulation (microencapsulated vs wax matrix).
Duration of ActionIV: 30-60 minutes; oral: 6-8 hours (sustained-release formulations).
Molecular Weight74.55

Classification & Brands

Dosing & administration

Oral: 40-100 mEq/day in divided doses; IV: up to 10-20 mEq/hour via central line, max 40 mEq/hour with continuous monitoring; not to exceed 200 mEq/day.

Dosage formTABLET, EXTENDED RELEASE
Renal impairmenteGFR >50: no adjustment; eGFR 10-50: reduce dose by 25-50%; eGFR <10: avoid or use with extreme caution, starting at 50% of usual dose.
Liver impairmentNo specific adjustment required for Child-Pugh A, B, or C; monitor potassium levels closely due to risk of hyperkalemia.
Pediatric useOral: 1-3 mEq/kg/day in divided doses; IV: 0.25-0.5 mEq/kg/hour, max 1 mEq/kg/hour with cardiac monitoring; max daily dose 3 mEq/kg/day.
Geriatric useStart at low end of adult dosing (e.g., 20 mEq/day) and titrate slowly; monitor renal function and potassium levels frequently due to decreased renal reserve.

Use during pregnancy

1st trimesterPotassium chloride is safe and essential in pregnancy when used at physiological doses to correct or prevent hypokalemia. Excess can cause hyperkalemia, which may lead to maternal cardiac arrhythmias and potentially affect fetal oxygenation. No teratogenic effects reported.
2nd trimesterSafe when used appropriately for hypokalemia. Monitor serum potassium to avoid hyperkalemia. Fetal risk is indirect via maternal electrolyte imbalance.
3rd trimesterSafe if indicated for hypokalemia. Hyperkalemia near term may cause maternal complications (e.g., arrhythmias) that could compromise fetal well-being. Use with caution in preeclampsia or renal impairment.

Clinical note

Comprehensive clinical and safety monograph for POTASSIUM CHLORIDE (POTASSIUM CHLORIDE).

Placental transferPotassium readily crosses the placenta by active transport and diffusion, reaching equilibrium with maternal serum levels. Fetal levels are slightly higher than maternal. Transfer is not a safety concern except in cases of maternal hyperkalemia.
BreastfeedingPotassium is a normal constituent of breast milk; supplementation at therapeutic doses does not increase levels significantly. Potassium chloride is considered compatible with breastfeeding. Monitor infant for signs of hyperkalemia if high maternal doses are used, though rare.
Lactation RatingL1 (Safe)
Teratogenic RiskPotassium chloride is not teratogenic. There is no evidence of fetal harm from oral or intravenous administration at therapeutic doses, provided maternal potassium levels are maintained within normal range. No trimester-specific risks identified; however, maternal hypokalemia or hyperkalemia can adversely affect fetal outcomes (e.g., arrhythmias, growth restriction).
Fetal MonitoringMonitor serum potassium levels regularly, especially in women with renal impairment, preeclampsia, or on medications affecting potassium (e.g., ACE inhibitors, potassium-sparing diuretics). Assess renal function and urine output. Fetal monitoring not routinely required; consider fetal heart rate monitoring if maternal electrolyte disturbances occur.
Fertility EffectsNo known adverse effects on fertility. Potassium chloride is a normal physiological electrolyte and does not impair reproductive function when used therapeutically.

Warnings & precautions

■ FDA Black Box Warning

Potassium chloride injection concentrate must be diluted before use. Undiluted administration can result in fatal cardiac arrest. Also, potassium supplements should not be used in patients with hyperkalemia or conditions that predispose to hyperkalemia.

Side Effect Profile

Serious Effects

Absolute Contraindications

Hyperkalemia (serum potassium >5.0 mEq/L)Severe renal impairment (e.g., anuria, oliguria, CrCl <30 mL/min)Addison's diseaseConcomitant use of potassium-sparing diuretics (e.g., spironolactone, eplerenone, amiloride, triamterene)Severe hemolytic reactionsAcute dehydrationHeat cramps due to excessive sweating (potassium loss is minimal; sodium replacement is primary)

Clinical Precautions

PrecautionsCardiac arrest if administered too rapidly or in concentrated form, Hyperkalemia risk especially in renal impairment, diabetes, or concurrent use of ACE inhibitors, ARBs, NSAIDs, or potassium-sparing diuretics, Gastrointestinal irritation with oral solid formulations; use with caution in patients with esophageal compression or delayed GI transit, Monitor serum potassium and ECG during parenteral therapy, Avoid potassium chloride in patients with severe burns, crush injuries, or other conditions that lead to rapid cellular breakdown
Food/DietaryAvoid potassium-rich foods in excess (e.g., bananas, oranges, tomatoes, potatoes, spinach, avocados, dried fruits, salt substitutes) unless instructed by your doctor. Do not take with alcohol or excessive coffee/tea, which may affect electrolyte balance.

Clinical Tips & Counseling

Clinical PearlsPotassium chloride is the preferred salt for replacement due to high chloride content which corrects metabolic alkalosis. Always administer IV potassium at a rate not exceeding 10-20 mEq/hour peripherally, and 10-40 mEq/hour centrally with continuous ECG monitoring. Never give IV potassium undiluted; maximum concentration for peripheral IV is 10 mEq/100 mL. In severe hypokalemia (K+ < 2.5 mEq/L), consider cardiac monitoring and admission. Oral potassium should be taken with food to minimize gastric irritation. Caution in renal impairment and with potassium-sparing diuretics or ACE inhibitors.
Patient AdviceTake potassium chloride with food or after a meal to prevent stomach upset. · Do not crush or chew extended-release tablets; swallow whole with a full glass of water. · Use the oral solution only if it is clear; do not mix with other drinks without asking your doctor. · Do not use salt substitutes (which contain potassium) while taking potassium supplements unless directed. · Report symptoms of high potassium levels: muscle weakness, irregular heartbeat, tingling in hands/feet, or confusion. · Keep all appointments for blood tests to monitor your potassium levels. · Store at room temperature away from moisture and heat.

POTASSIUM CHLORIDE Interactions

Loading safety data…

This overview is compiled from peer-reviewed clinical sources and FDA labeling. It's here to support — not replace — clinical judgment. Always verify dosing against your institution's current protocols before prescribing.

On this page

Mechanism of ActionDosing & administrationUse during pregnancyWarnings & precautionsDrug interactions

Compare with

CALCIUM CHLORIDE 10%CALCIUM CHLORIDE 10% IN PLASTIC CONTAINERCALCIUM GLUCEPTATECALCIUM GLUCONATEHEMICLOR

External sources

DailyMed (NIH) PubMed OpenFDA