Potassium Disturbances

Clinical Snapshot

Potassium is the major intracellular cation in the body, obtained from dietary sources such as fruit, vegetables, fish, and meat, with a typical daily intake of 50-100 mmol. Normal plasma potassium is 3.5-5 mmol/L, and this narrow range is maintained by both total-body potassium stores and rapid, reversible shifts of potassium between the intracellular and extracellular compartments — driven by insulin, beta-adrenergic tone, and acid-base status — so a single plasma value can reflect either a true total-body deficit/excess or a transient shift, and management differs depending on which is present. Hyperkalemia (plasma potassium over 5 mmol/L: mild 5-6, moderate 6.1-6.5, severe over 6.5 mmol/L) and hypokalemia (plasma potassium under 3.5 mmol/L: mild 3-3.5, moderate 2.5-3, severe under 2.5 mmol/L) both matter clinically for the same core reason — either direction can produce potentially fatal cardiac arrhythmias, alongside musculoskeletal, neurologic, and psychiatric complications — and the urgency of treatment is driven as much by ECG findings, rate of change, and concurrent risk factors as by the lab value itself.^[1]

Recognize the Condition

Both directions of potassium disturbance can be entirely asymptomatic and detected only on routine bloodwork, especially at mild severity — clinical suspicion and severity staging both matter for deciding how urgently to act.^[2]

The two directions of potassium disturbance

Hyperkalemia

Severity: mild 5-6 mmol/L, moderate 6.1-6.5 mmol/L, severe over 6.5 mmol/L.

Often clinically silent, especially at mild severity — many patients are identified on routine labs rather than by symptoms.
Muscle weakness or ascending flaccid paralysis at higher severity, which can be mistaken for a primary neurologic process.
Paresthesias.
Palpitations, bradyarrhythmia, or cardiac arrest — the dominant clinical concern, and possible even without dramatic ECG changes at a given lab value.

Hypokalemia

Severity: mild 3-3.5 mmol/L, moderate 2.5-3 mmol/L, severe under 2.5 mmol/L.

Fatigue, muscle weakness, cramps, and constipation are the most common minor symptoms.
Paresthesias.
Palpitations and arrhythmia risk, which increases sharply with concurrent digoxin therapy.
At severe levels: rhabdomyolysis, respiratory muscle weakness, and — rarely — ascending paralysis.

Risk Factors

Causes and risk factors, by direction

Hyperkalemia

Drug-induced: ACE inhibitors, ARBs, potassium-sparing diuretics (especially steroidal and nonsteroidal mineralocorticoid receptor antagonists), NSAIDs, trimethoprim (alone or as trimethoprim-sulfamethoxazole, especially at high dose or in susceptible patients — older adults, kidney impairment), potassium supplements, potassium-containing salt substitutes, beta-blockers, cyclosporine, tacrolimus, digoxin overdose, heparin, ketoconazole, pentamidine, succinylcholine, penicillin G potassium, aminocaproic acid, and drospirenone-containing products.
Acidosis.
Crush injury, trauma, hemolysis, tumor lysis syndrome, and massive transfusion — situations of rapid intracellular potassium release.
Disease-induced: kidney failure, diabetes, adrenal insufficiency, hyporeninemic hypoaldosteronism.
Family history of hyperkalemia.
Herbal and nutritional supplements — alfalfa, nettle, noni juice, Siberian ginseng — especially in the presence of kidney failure.

Hypokalemia

Drug-induced: acetazolamide, aminoglycosides, amphotericin B, antipseudomonal penicillins, beta2-agonists, caffeine, foscarnet, insulin, laxatives, licorice, long-term systemic corticosteroid therapy, loop and thiazide diuretics, theophylline, and tocolytic agents.
Cushing syndrome.
Dialysis or plasmapheresis.
Family history — Bartter or Gitelman syndrome.
Hypomagnesemia.
Inadequate dietary intake.
Increased losses: diarrhea, sweat, ileostomy output, osmotic diuresis (e.g., poorly controlled diabetes), or vomiting.
Metabolic alkalosis.
Mineralocorticoid excess, e.g., primary aldosteronism.
Renovascular disease — both large-vessel (e.g., renal artery stenosis) and small-vessel (e.g., scleroderma).

Red Flags & Refer

Either direction of potassium disturbance can be a true medical emergency — the criteria below identify when it is.

Hyperkalemia with ECG changes (loss of P waves, QRS widening, or more advanced changes) or cardiac arrhythmia — a true emergency requiring immediate stabilization, not routine outpatient management.
Severe hypokalemia (under 2.5 mmol/L) with arrhythmia or significant ECG changes (U waves, T-wave flattening, ST-segment changes) — requires urgent, monitored correction.
A potassium level, in either direction, associated with muscle weakness or paralysis — respiratory muscle involvement in particular can progress to respiratory failure.
Rapid IV potassium infusion causing a cardiac arrhythmia if given too fast — stop the infusion immediately and manage as an acute arrhythmia.
Hyperkalemia in a dialysis patient who has missed a scheduled session, or any situation with rapid, ongoing intracellular potassium release (rhabdomyolysis, tumor lysis syndrome, massive hemolysis) — the rate of rise is itself dangerous, independent of the absolute level.
Hypokalemia with concurrent digoxin therapy — significantly increases the risk of digoxin-related arrhythmia at an otherwise unremarkable potassium level.

Assessment & Diagnosis

Rule out pseudohyperkalemia before treating an unexpectedly high result. Hemolysis during or after venipuncture is the most common cause and is usually visually apparent in the sample — repeat the draw without a tourniquet and without excessive forearm/fist clenching, since repeated muscle contraction increases potassium efflux. Thrombocytosis and severe leukocytosis can also cause a spuriously high result, since potassium leaks from platelets and white cells as the sample clots — the longer the sample stands before analysis, the greater the apparent rise. A result inconsistent with the clinical picture should be repeated before any treatment is given.^[3]

History

Directed at etiology — see the causes listed in Risk Factors for each direction.
Ask about muscle weakness, paresthesias, palpitations, and features suggesting the specific mechanisms above (diuretic or supplement use, GI losses, dietary intake, licorice or herbal supplement use, family history).

Physical examination

Cardiac rhythm, muscle strength, and paresthesias.
Blood pressure — consider hyperaldosteronism when hypokalemia coexists with hypertension.
Extracellular fluid volume (ECFV) status, assessed indirectly since total body sodium heavily influences potassium handling: edema, hypertension, elevated jugular venous pressure (JVP), ascites, and pleural effusions suggest ECFV expansion; poor skin turgor, hypotension (especially a postural drop), and decreased JVP suggest ECFV contraction.

ECG

Obtain when clinically necessary — severe hyperkalemia or hypokalemia, or any symptomatic presentation. In hyperkalemia, the classic progression is peaked T waves, then PR-interval prolongation and P-wave flattening/loss, then QRS widening, then a sine-wave pattern preceding ventricular fibrillation or asystole — though isolated peaked T waves may not be significant, and the prognostic value of ECG changes overall is not absolute. In hypokalemia, look for U waves, T-wave flattening, and ST-segment changes, which signal increased arrhythmia risk, including torsades de pointes.

Laboratory testing

Urea, creatinine, sodium, potassium, chloride, and glucose.
Magnesium — essential in refractory hypokalemia, especially in patients at risk of hypomagnesemia (alcohol use disorder, diarrhea, or use of cisplatin, diuretics, or a proton pump inhibitor).
Arterial or venous blood gas, or total CO2 — systemic pH has a major effect on transcellular potassium movement.
Urine sodium, potassium, chloride, and osmolality to calculate the transtubular potassium gradient (TTKG) and the potassium-creatinine ratio, and a 24-hour urine collection for sodium, potassium, and creatinine in select cases.
Aldosterone, cortisol, renin, adrenal disease screening, TSH (thyrotoxicosis), kidney ultrasound, and renal artery imaging in select cases where the cause remains unclear after initial workup.

These further investigations are for identifying an unclear underlying cause, not for guiding acute treatment — do not delay emergency stabilization while awaiting results.^[4]

Treatment Targets

Prevent life-threatening cardiac arrhythmias and preserve neuromuscular conduction.
Re-establish normal total-body potassium stores and prevent ongoing loss or accumulation.
Identify and correct the underlying cause rather than treating the lab value in isolation.
In hyperkalemia specifically: avoid iatrogenic hypoglycemia during insulin-based redistribution therapy.
In hypokalemia specifically: correct any concurrent magnesium deficit, since potassium correction is often incomplete or transient until magnesium is also normalized.

Choose Initial Treatment

Direct treatment rule

Hyperkalemia — treat by ECG findings and severity, not the lab value alone

Do not rely on the plasma potassium level or the ECG alone to judge urgency — cardiac toxicity also depends on the rate of rise, chronicity, concurrent hypocalcemia/hyponatremia/acidosis (all increase cardiotoxicity), and underlying cardiac irritability; weigh all of these together.

1st step for ECG changes or cardiac instability — for hyperkalemia with ECG changes (loss of P waves, QRS widening, or more advanced change) or hemodynamic/cardiac instability at any potassium level, begin continuous ECG monitoring and give IV calcium (gluconate or chloride) immediately for membrane stabilization before any other measure — it does not lower serum potassium but protects the heart while redistribution and elimination therapies take effect.

Give calcium and a redistribution agent simultaneously, not sequentially: for severe hyperkalemia (over 6.5 mmol/L) or significant ECG change, give IV regular insulin as a bolus with concurrent dextrose to prevent hypoglycemia — insulin is the preferred redistribution agent given reliable efficacy and a limited side-effect profile; use an insulin infusion instead of a bolus when the situation is less urgent.^[5]

Give the dextrose component over at least 5 minutes, never faster — an acute rise in plasma tonicity from rapid dextrose administration can transiently raise, not lower, plasma potassium. Expect roughly a 1-1.5 mmol/L fall in plasma potassium over about 60 minutes with insulin-based therapy, and monitor plasma glucose closely to avoid overtreating into hypoglycemia.

Adjunct — nebulized or IV salbutamol adds to the potassium-lowering effect of insulin and can be used as an additional redistribution agent, but reserve it for patients at low cardiac risk or for life-threatening situations when other therapies have failed, since it is arrhythmogenic and can exacerbate angina; up to half of patients with chronic kidney failure show a blunted response to the nebulized route.

Special situation — reserve sodium bicarbonate for hyperkalemia with significant concurrent metabolic acidosis; it has a synergistic effect with insulin when acidosis is present but a smaller effect without it. Give calcium first if hypocalcemia is present, since correcting acidosis in a hypocalcemic patient can precipitate tetany, and avoid hypertonic bicarbonate solutions given their own risk of an acute osmolality-driven rise in plasma potassium.

Begin potassium elimination at the same time as stabilization and redistribution therapy, not afterward: a loop diuretic with adequate fluid replacement if kidney function allows; a potassium binder for ongoing removal — sodium zirconium cyclosilicate has a faster onset (within about 1 hour) than patiromer (roughly 7 hours) and may be preferable when rapid lowering is needed^[6], though both are effective for sustained potassium control^[7]^[8]; and hemodialysis for severe or refractory hyperkalemia, or whenever a large potassium load must be removed rapidly — begin dialysis preparation early, since equipment and access setup takes time, and continue other measures while preparing.

Mild hyperkalemia without ECG change or instability (5-6 mmol/L) usually resolves over a few days with nonpharmacologic measures alone — stop potassium supplements and hyperkalemia-inducing drugs, and reduce dietary potassium to 60 mmol/day or under; escalate to redistribution/elimination therapy if the level continues to rise, if there is ongoing potassium input (GI bleeding, hematoma resorption, hemolysis), or if kidney failure is present.

Hypokalemia — select the route and rate by urgency, and correct magnesium at the same time

Oral potassium chloride is preferred whenever the GI tract is usable and urgent correction is not required — a liquid preparation (40-60 mmol) raises plasma potassium by roughly 1-1.5 mmol/L within hours. Reserve IV replacement for patients who cannot take oral potassium (paralytic ileus, postsurgical) or who require urgent correction (respiratory muscle weakness, cardiac arrhythmia — especially with concurrent digoxin, hepatic encephalopathy risk).

IV potassium maximum infusion rate — a safety-critical limit, not a target to reach routinely: do not exceed 10 mmol/hour through a standard peripheral line without continuous ECG monitoring and frequent serum potassium measurement. Administer through a large peripheral vein at a maximum concentration of 40-60 mmol/L; higher concentrations require a central line with the catheter tip positioned away from the right atrium/ventricle to avoid direct effects on cardiac membrane potential. In genuinely life-threatening hypokalemia (severe symptomatic deficit, respiratory muscle weakness, dangerous arrhythmia), faster rates — 20-40 mmol in the first hour, with doses over 40 mmol/hour reported in life-threatening cases — have been used under continuous ECG monitoring and frequent serum potassium measurement; this is an exception for genuinely urgent presentations, never a routine rate.^[9]

Once plasma potassium reaches about 3 mmol/L, slow the infusion and correct the remaining deficit more gradually — the total-body deficit is substantial even at moderate plasma levels (roughly 200-400 mmol at a plasma potassium of 3 mmol/L, and 500-700 mmol at 2 mmol/L), so replacement is a multi-dose process guided by repeat levels, not a single calculated dose.

Use a dextrose-free IV solution for potassium replacement in severe hypokalemia — dextrose stimulates insulin secretion, which shifts additional potassium intracellularly and can transiently worsen the deficit being corrected.

Check and replace magnesium at the same time as potassium whenever magnesium status is unknown or low. Hypokalemia is often refractory to potassium repletion alone until magnesium is also corrected — hypomagnesemia increases renal potassium wasting and impairs the Na+/K+-ATPase pump that potassium needs to re-enter cells, so potassium given without correcting a coexisting magnesium deficit may simply be lost again.^[10]

In diabetic ketoacidosis specifically, correct potassium depletion before giving insulin or bicarbonate — both agents can drive potassium further into cells and worsen hypokalemia, which is already a risk in DKA given the underlying total-body deficit.

Non-Pharmacologic Treatment

Non-pharmacologic measures, by direction

Hyperkalemia

Stop potassium supplements and drugs that cause hyperkalemia (see Risk Factors); resume any necessary agent at a reduced dose only once the hyperkalemia has resolved.
Reduce dietary potassium intake to 60 mmol/day or under.
These measures alone are usually sufficient for mild hyperkalemia (5-6 mmol/L) without ECG changes or instability.

Hypokalemia

If clinically appropriate, reduce or stop the medication responsible for potassium loss.
Identify and treat the underlying etiology; assess dietary potassium intake.
For a mild deficit (3-3.5 mmol/L) with no ongoing losses or a condition warranting prompt treatment, dietary potassium-rich foods are usually adequate; if losses are ongoing, oral potassium supplementation or a potassium-sparing diuretic will be needed instead.
Do not routinely combine an oral potassium supplement with a potassium-sparing diuretic — the combination substantially increases hyperkalemia risk; if temporarily required at the start of replacement therapy for very high ongoing kidney losses, monitor plasma potassium at least daily and stop one of the two agents once potassium reaches 3-3.5 mmol/L.

Pharmacologic Treatment Options

Drug / intervention	Role	Dose / use	Important adverse effects	Teaching points
Calcium gluconate Preferred	Membrane stabilization, hyperkalemia with ECG changes/instability	10 mL of a 10% solution IV over 2-5 minutes; may repeat once after 5 minutes depending on ECG	Local tissue necrosis if extravasated; bradycardia if infused too fast; incompatible with sodium bicarbonate in the same line	Give first, before or simultaneously with insulin, whenever ECG changes are present — it stabilizes the cardiac membrane but does not lower plasma potassium.
Calcium chloride Alternative	Membrane stabilization alternative, cardiac arrest/central access	5-10 mL of a 10% solution IV over 2-5 minutes; may repeat once after 5 minutes	Significant tissue necrosis risk if extravasated (roughly 3-fold more elemental calcium per mL than gluconate); bradycardia if infused too fast	Reserve for cardiac arrest or established central access given the higher extravasation risk.
Regular insulin + dextrose Preferred	Redistribution, 1st choice for hyperkalemia	Combo: Regular insulin 5-10 units IV bolus + dextrose 25-50 g IV over at least 5 minutes	Hypoglycemia	Use an infusion (10 units in 500 mL dextrose 10% at 50-100 mL/hour) instead of a bolus if less urgent. Monitor glucose closely; expect roughly a 1-1.5 mmol/L fall in potassium within 60 minutes.
Salbutamol Alternative	Adjunct redistribution agent	Nebulized 10-20 mg, or 12 puffs (1200 mcg) by MDI with spacer	Tachycardia, arrhythmia, angina	Reserve for low cardiac-risk patients or when other therapies have failed. Up to half of patients with chronic kidney failure have a blunted response to the nebulized route.
Furosemide Preferred	Potassium elimination via the kidney, adequate kidney function	40-250 mg PO/IV depending on kidney function	Volume depletion; transient ototoxicity with high-dose IV use	Give with adequate fluid replacement to avoid volume contraction.
Sodium zirconium cyclosilicate Preferred	Potassium binder, faster onset than patiromer	Acute: 10 g PO TID. Maintenance: 5 g every other day to 10 g daily	Edema (dose-related), GI upset	Onset within about 1 hour — preferred over patiromer when faster lowering is needed.
Patiromer Alternative	Potassium binder, slower onset	8.4 g PO daily with a meal initially; titrate to a maximum of 25.2 g PO daily based on response	Constipation, flatulence, hypomagnesemia	Onset roughly 7 hours — not preferred as the sole binder in a true acute emergency.
Sodium polystyrene sulfonate Special situation	Older cation-exchange resin, potassium binder	15-60 g PO in water or 20% sorbitol every 4-6 hours PRN (usual dose 30 g); or 30-50 g PR every 4-6 hours PRN	Constipation; rare but serious bowel ulceration or colonic necrosis, particularly with sorbitol	Reserve for when the newer binders are unavailable or unaffordable. Avoid combining with sorbitol.
Potassium chloride, oral Preferred	1st-line hypokalemia repletion when the GI tract is usable	40-60 mmol/day PO in divided doses	Unpleasant taste; GI upset; rare esophageal ulceration with a wax-matrix tablet	Preferred route and salt of choice, especially in alkalotic patients. Avoid combining routinely with a potassium-sparing diuretic.
Potassium chloride, intravenous Special situation	Urgent or parenteral hypokalemia correction	Max 10 mmol/hour peripherally (concentration 40-60 mmol/L) routinely; up to 40 mmol/hour with central access and continuous ECG monitoring in life-threatening cases	Infusion-site pain/sclerosis; arrhythmia if infused too fast	Use a dextrose-free diluent in severe hypokalemia. Reserve for inability to tolerate oral or genuinely urgent correction.

Special Populations

Pregnancy

Potassium disturbances are assessed and treated in pregnancy using the same severity thresholds, ECG-driven urgency, and emergency-stabilization sequence as in a non-pregnant adult — there is no pregnancy-specific dose adjustment for calcium, insulin/dextrose, furosemide, or potassium chloride. Normal pregnancy involves mild physiologic changes in potassium handling from expanded plasma volume and altered renin-angiotensin-aldosterone activity, so a mildly low-normal potassium in an otherwise well pregnant patient does not automatically require treatment. ACE inhibitors and ARBs — already relevant hyperkalemia-causing drugs outside pregnancy — are separately contraindicated in pregnancy for teratogenicity reasons and should already be held regardless of the potassium indication.

Breastfeeding

Calcium, insulin/dextrose, furosemide, salbutamol, and standard oral/IV potassium replacement are all considered compatible with breastfeeding at usual doses. Data on the newer potassium binders (patiromer, sodium zirconium cyclosilicate) in lactation are limited, though systemic absorption from either agent is expected to be minimal given their non-absorbed, gut-acting mechanism.

Pediatrics

Potassium replacement in children is weight-based and must be individualized under pediatric or pediatric nephrology guidance — the adult mmol-based dosing and infusion-rate limits in this chapter's Drug Tables must not be extrapolated directly to a child. Not established in this source for routine pediatric dosing.

Renal impairment

Kidney failure is one of the most common causes of hyperkalemia and requires earlier, more aggressive treatment given impaired renal potassium excretion; dialysis is the definitive treatment for severe or refractory cases. Sodium zirconium cyclosilicate and patiromer are both effective for maintaining normokalemia in chronic kidney disease, including in patients continued on a RAAS inhibitor; dose-related edema with sodium zirconium cyclosilicate can usually be managed with dose reduction or diuretic therapy. Potassium-sparing diuretics should generally be avoided in significant kidney impairment given the markedly increased hyperkalemia risk.

Older adults and hepatic impairment

Older adults are at increased hyperkalemia risk with ACE inhibitor/ARB and potassium-sparing diuretic combinations — monitor closely (see Monitoring and Follow-up). In hepatic insufficiency, correct hypokalemia promptly, since it increases the risk of hepatic encephalopathy; IV replacement is a recognized urgent indication in this population when oral intake is inadequate.^[4]

Monitoring & Follow-Up

Monitor plasma potassium frequently during any active correction — after each 20-40 mmol IV dose of potassium chloride in hypokalemia, and repeatedly through the elimination phase of hyperkalemia treatment (loop diuretic, binder, or dialysis). Monitor plasma glucose closely during insulin-based redistribution therapy for hyperkalemia. Use continuous ECG monitoring throughout IV calcium administration and during any potassium infusion above the routine peripheral rate limit.

After starting or changing the dose of a hyperkalemia-inducing medication — particularly an ACE inhibitor, ARB, or potassium-sparing diuretic, and especially the combination of a RAAS inhibitor with spironolactone — check potassium at 3 and 7 days, then check creatinine and potassium at 1 week and 4 weeks, and every 6 months thereafter if stable. This monitoring schedule matters most in patients already at elevated hyperkalemia risk: kidney failure, older age, and cardiac insufficiency.^[4]

For chronic or recurrent hyperkalemia, focus follow-up on the underlying cause or pathophysiologic mechanism rather than repeated acute treatment — the same agents used acutely (diuretics, sodium bicarbonate, potassium binders) are also used for ongoing chronic management.

Treatment Failure / Next Step

For hyperkalemia not responding as expected: confirm adherence to the dietary and medication changes already made, and rule out ongoing potassium input — GI bleeding, resolving hematoma, hemolysis, tumor lysis, or rhabdomyolysis.
Reassess kidney function — worsening kidney failure both raises potassium and blunts the response to loop diuretics and binders.
Escalate elimination therapy — add or switch to a potassium binder, and move to dialysis without further delay if hyperkalemia is severe, refractory, or accompanied by ongoing large potassium input.
For hypokalemia refractory to potassium repletion alone: check and correct magnesium — this is the single most common reason apparently adequate potassium replacement fails to raise the level.
Reassess for ongoing renal or GI losses, and review whether a potassium-wasting diuretic or another causative drug is still being given unnecessarily.
If hypokalemia is refractory and accompanied by hypertension, investigate for mineralocorticoid excess (e.g., primary aldosteronism) rather than continuing to escalate potassium dosing alone.

Common Errors to Avoid

Delaying IV calcium while waiting on additional labs when ECG changes are already present — calcium is a bedside, immediate-action drug.
Giving the dextrose component of insulin/dextrose therapy too quickly — an acute rise in plasma tonicity can transiently raise, not lower, plasma potassium; give over at least 5 minutes.
Relying on nebulized salbutamol alone as the sole hyperkalemia therapy — response is variable, and roughly half of patients with chronic kidney failure are relatively resistant to the nebulized route.
Mixing calcium and sodium bicarbonate in the same IV line — they are incompatible and will precipitate.
Infusing IV potassium chloride faster than the peripheral safety limit without central access and continuous ECG monitoring — risks both arrhythmia and vein sclerosis.
Combining an oral potassium supplement with a potassium-sparing diuretic without frequent monitoring — a well-recognized cause of severe, sometimes unexpected hyperkalemia.
Treating hypokalemia with potassium alone while ignoring a concurrent magnesium deficit — correction will be incomplete or transient.
Treating a hyperkalemic lab result without considering pseudohyperkalemia (hemolysis, thrombocytosis, or leukocytosis) first, especially when the result doesn't fit the clinical picture.
Correcting severe hypokalemia with concurrent hyponatremia too quickly with potassium chloride — both cations count toward total body tonicity, so rapid potassium correction can rapidly correct the hyponatremia as well and precipitate osmotic demyelination.
In diabetic ketoacidosis, giving insulin or bicarbonate before addressing potassium depletion — both agents can worsen hypokalemia that is often already present.

Clinical Decision Algorithm

Hyperkalemia management

Confirmed hyperkalemia (plasma K+ over 5 mmol/L) — rule out pseudohyperkalemia first (hemolysis, thrombocytosis, leukocytosis)

Obtain ECG; assess severity (mild 5-6, moderate 6.1-6.5, severe over 6.5 mmol/L), rate of rise, and chronicity

ECG changes present, severe hyperkalemia, or hemodynamic/cardiac instability

Continuous ECG monitoring. Give IV calcium gluconate (or chloride) immediately for membrane stabilization

Simultaneously give IV regular insulin bolus with dextrose, given over at least 5 minutes; monitor glucose closely

Add nebulized/IV salbutamol as adjunct if needed; add sodium bicarbonate only if significant metabolic acidosis is present (give calcium first if hypocalcemic)

Begin potassium elimination simultaneously — loop diuretic if kidney function allows, potassium binder, and prepare for dialysis if severe or refractory

Dialysis is the treatment of choice for rapidly removing a large potassium load — begin preparation early given setup time

Mild hyperkalemia (5-6 mmol/L), no ECG changes, no instability

Stop/hold potassium supplements and hyperkalemia-inducing drugs; reduce dietary potassium to 60 mmol/day or under

Resolves over several days

Continue monitoring; resume held medications at a reduced dose once resolved, if appropriate

Rising K+, ongoing potassium input (GI bleed, hematoma, hemolysis), or kidney failure

Escalate to redistribution and elimination therapy as in the left-hand branch

Hypokalemia management

Confirmed hypokalemia (plasma K+ under 3.5 mmol/L) — identify etiology and check magnesium status

Urgent: respiratory muscle weakness, cardiac arrhythmia, severe symptomatic hypokalemia (under 2.5 mmol/L), digitalis toxicity, DKA, or hepatic encephalopathy risk

Continuous ECG monitoring. IV potassium chloride 20-40 mmol in the first hour (up to 40 mmol/hour reported in life-threatening cases); large peripheral vein, max concentration 40-60 mmol/L, or central line at lower concentration

Never exceed a routine 10 mmol/hour peripheral infusion rate without continuous ECG and frequent K+ monitoring

Once plasma K+ reaches about 3 mmol/L, slow the infusion and correct the remaining deficit more gradually

Less urgent: plasma K+ 2.5-3 mmol/L, no severe symptoms

IV potassium chloride 10-20 mmol over 1 hour (raises K+ by about 0.25-0.5 mmol/L); IV route also if severe nausea/vomiting or unable to tolerate oral

Not urgent: plasma K+ over 3 mmol/L, mild or no symptoms

Oral potassium chloride 40-60 mmol/day in divided doses; dietary potassium-rich foods alone if the deficit is mild with no ongoing losses

Check serum magnesium in every case; replace magnesium concurrently if low or unknown — hypokalemia is often refractory until magnesium is also corrected

In DKA specifically: correct potassium before giving insulin or bicarbonate, since both can worsen hypokalemia

Drug Tables

How to use this table: Doses are adult doses and require patient-specific confirmation (renal/hepatic function, weight, allergy history). Pediatric dosing is weight-based per the current product monograph unless stated. Drug pricing is intentionally omitted. Select any drug name to open its complete Pharmasist Drug Database page.

Beta2-Adrenergic Agonists

Adjunct redistribution therapy for hyperkalemia.

Drug	Dosage	Adverse effects	Drug interactions	Comments
Salbutamol	Adults, nebulized: 10-20 mg by nebulizer Adults, MDI with spacer: 1200 mcg (12 puffs) Children: Not established for this indication — pediatric/specialist-directed only.	Tachycardia, arrhythmia, angina, tremor	Caution with other arrhythmogenic drugs; effect is additive with insulin-based redistribution therapy	Reserve for low cardiac-risk patients or life-threatening situations when other therapies have failed — arrhythmogenic. Up to half of patients with chronic kidney failure show a blunted response to the nebulized route; MDI with spacer is also effective.

Loop Diuretics

Potassium elimination via the kidney, hyperkalemia.

Drug	Dosage	Adverse effects	Drug interactions	Comments
Furosemide	Adults: 40-250 mg PO/IV depending on kidney function Children: Standard weight-based diuretic dosing — not detailed in this source for the hyperkalemia indication specifically.	Volume depletion; transient ototoxicity with high-dose IV use	Additive potassium loss with other potassium-wasting diuretics; caution with other ototoxic drugs at high IV doses	Give with adequate fluid replacement to avoid volume contraction. Effective only with adequate kidney function.

Electrolytes — Membrane Stabilization and Redistribution

For hyperkalemia with ECG changes or metabolic acidosis.

Drug	Dosage	Adverse effects	Drug interactions	Comments
Calcium gluconate	Adults: 10 mL of a 10% solution IV over 2-5 minutes; may repeat once after 5 minutes depending on ECG Children: Weight-based dosing under pediatric/critical-care direction — not detailed in this source.	Tissue necrosis if extravasated; bradycardia if infused too fast	Incompatible with sodium bicarbonate-containing solutions (precipitation); infuse more slowly in patients on digoxin given increased digoxin toxicity risk	Continuous ECG monitoring required. 1 g calcium gluconate = 93 mg (4.6 mEq, 2.3 mmol) elemental calcium. Preferred over calcium chloride for peripheral administration given lower extravasation risk.
Calcium chloride	Adults: 5-10 mL of a 10% solution IV over 2-5 minutes; may repeat once after 5 minutes depending on ECG Children: Weight-based dosing under pediatric/critical-care direction — not detailed in this source.	Significant tissue necrosis if extravasated; bradycardia if infused too fast	Incompatible with sodium bicarbonate-containing solutions (precipitation); infuse more slowly in patients on digoxin	Continuous ECG monitoring required. 1 g calcium chloride = 270 mg (14 mEq, 7 mmol) elemental calcium — roughly 3-fold more elemental calcium per mL than gluconate. Preferred in cardiac arrest with hyperkalemia, hypocalcemia, or magnesium toxicity, generally via central access.
Sodium bicarbonate	Adults: 50-100 mmol IV over 5 minutes; may repeat every 10-15 minutes depending on ECG Children: Weight-based dosing under pediatric/critical-care direction — not detailed in this source.	Risk of tetany if hypocalcemia is present and uncorrected; sodium overload	Incompatible with calcium-containing solutions (precipitation) — give calcium first if hypocalcemia is present	Reserve for hyperkalemia with significant concurrent metabolic acidosis — smaller effect without a low bicarbonate or pH. Avoid hypertonic solutions, which can themselves acutely raise plasma potassium through an osmolality effect.

Insulin

Redistribution, 1st-choice agent for hyperkalemia.

Drug	Dosage	Adverse effects	Drug interactions	Comments
Regular insulin (with dextrose)	Adults, urgent (bolus): Regular insulin 5-10 units IV + dextrose 25-50 g IV over at least 5 minutes Adults, less urgent (infusion): Insulin 10 units in 500 mL dextrose 10% IV, infused at 50-100 mL/hour Children: Weight-based dosing under pediatric/critical-care direction — not detailed in this source.	Hypoglycemia	Effect is additive with salbutamol; correcting acidosis (e.g., sodium bicarbonate) has a synergistic effect	The most reliable redistribution agent. Follow plasma glucose closely. Do not give the dextrose component faster than over 5 minutes — an acute rise in plasma tonicity can transiently increase plasma potassium. Expect roughly a 1-1.5 mmol/L fall in potassium within 60 minutes.

Potassium-Binding Agents

Elimination-phase therapy for hyperkalemia; effectiveness of the older cation-exchange resins is debated, and a concurrent laxative effect may account for much of their apparent benefit.

Drug	Dosage	Adverse effects	Drug interactions	Comments
Calcium polystyrene sulfonate	Adults, oral: 15 g 3-4 times daily, mixed into a paste with a sweetened vehicle Adults, rectal: 30 g in 100 mL methylcellulose 2% plus 100 mL water as a daily retention enema, retained for up to 9 hours if possible Children: Not established for routine pediatric use — individualize under pediatric/nephrology-directed weight-based dosing.	Constipation; risk of bowel ulceration or necrosis	Also binds magnesium; avoid concurrent sorbitol (colonic necrosis/intestinal obstruction risk); do not mix with orange juice or other high-potassium fruit juices	Preferred over the sodium salt when sodium overload is a concern (sodium content under 1 mg/g). Give a cleansing enema before and after rectal use.
Sodium polystyrene sulfonate	Adults, oral: 15-60 g in 50-200 mL of 20% sorbitol or water every 4-6 hours PRN; usual dose 30 g Adults, rectal: 30-50 g in 100-200 mL water or 10% dextrose every 4-6 hours PRN, retained at least 30-60 minutes Children: Not established for routine pediatric use — individualize under pediatric/nephrology-directed weight-based dosing.	Constipation; rare but serious bowel ulceration or colonic necrosis	Avoid concurrent sorbitol (colonic necrosis/intestinal obstruction risk); do not mix with orange juice or other high-potassium fruit juices	Sodium content is substantial (100 mg/g) — avoid if sodium overload is a concern. Give a cleansing enema before and after rectal use. Reserve for when the newer binders below are unavailable or unaffordable.
Sodium zirconium cyclosilicate	Adults, acute treatment: 10 g PO TID Adults, maintenance: 5 g every other day to 10 g PO daily Children: Not established for routine pediatric use — individualize under pediatric/nephrology-directed weight-based dosing.	Edema (dose-related); GI upset	No clinically significant drug interactions identified at recommended doses	Onset within about 1 hour — faster than patiromer. Mix the dose with 250 mL water. Sodium content 80 mg/g; dose-related edema can usually be managed with dose reduction or diuretic therapy.
Patiromer	Adults: 8.4 g PO daily initially with a meal, titrated to a maximum of 25.2 g PO daily based on response Children: Not established for routine pediatric use — individualize under pediatric/nephrology-directed weight-based dosing.	Constipation, flatulence; hypomagnesemia possible	May reduce absorption of other oral medications given at the same time — separate administration by several hours per the product monograph	Onset roughly 7 hours — the slowest-onset binder, not preferred as sole therapy in a true acute emergency. Mix the dose with 90 mL water and give with a meal. Store in the refrigerator; may be kept at room temperature for up to 3 months once removed.

Potassium Supplements, Intravenous

Reserve for urgent hypokalemia correction or inability to tolerate oral replacement.

Drug	Dosage	Adverse effects	Drug interactions	Comments
Potassium chloride, intravenous	Adults, urgent (severe/symptomatic): 20-40 mmol IV in the first hour with continuous ECG monitoring and frequent potassium measurement; doses over 40 mmol/hour have been reported in life-threatening hypokalemia Adults, less urgent: 10-20 mmol IV over 1 hour, with ECG monitoring if the rate is over 10 mmol/hour Children: Weight-based dosing under pediatric/critical-care direction — not detailed in this source.	Infusion-site pain and sclerosis; cardiac arrhythmia and other effects if infused too fast	Additive hyperkalemia risk with concurrent potassium-sparing diuretics, ACE inhibitors, ARBs, or potassium supplements	Administer via a large peripheral vein at a maximum concentration of 40-60 mmol/L; higher concentrations require central access with the catheter tip away from the right atrium/ventricle. Use a dextrose-free diluent in severe hypokalemia. Measure serum potassium after each 20-40 mmol dose.
Potassium phosphate, intravenous	Adults: Dose according to phosphate requirement, in 7.5 mmol increments, diluted and infused over 4-12 hours; maximum single dose 45 mmol phosphate (66 mmol potassium) Children: Weight-based dosing under pediatric/critical-care direction — not detailed in this source.	Sclerosis; cardiac arrhythmias; hypocalcemia	Additive hyperkalemia risk with other potassium-containing products	Reserve for hypokalemia with a concurrent significant phosphate deficit. Must be diluted in a compatible IV fluid before administration. Each mmol of phosphate delivers roughly 1.5 mmol of potassium — monitor both serum potassium and phosphate.

Potassium Supplements, Oral

Preferred route whenever the GI tract is usable and urgent correction is not required.

Drug	Dosage	Adverse effects	Drug interactions	Comments
Potassium chloride, oral	Adults, not urgent (K+ over 3-3.5 mmol/L): 40-60 mmol/day PO in 2-4 divided doses Children: Not established for routine pediatric use — individualize under pediatric/nephrology-directed weight-based dosing.	Unpleasant taste and aftertaste (liquid/powder); GI upset; rare esophageal or GI ulceration, particularly with the wax-matrix tablet	Avoid combining with a potassium-sparing diuretic without frequent monitoring — substantially increases hyperkalemia risk	Preferred salt of choice, especially in alkalotic patients — rapid absorption, good bioavailability. Available as liquid/powder, micro-encapsulated capsules, or a wax-matrix tablet — dosing is equivalent by mmol content. Avoid the micro-encapsulated or wax-matrix forms in delayed GI transit or impaired esophageal/intestinal motility.
Potassium citrate	Adults: 40-60 mmol/day PO in divided doses Children: Not established for routine pediatric use — individualize under pediatric/nephrology-directed weight-based dosing.	Unpleasant taste and aftertaste; nausea, heartburn	Avoid combining with a potassium-sparing diuretic without frequent monitoring	Reserve for hypokalemic patients with concurrent metabolic acidosis (e.g., renal tubular acidosis, diarrhea) or thiazide-associated hypokalemia in patients being treated for kidney stones — also increases urinary citrate excretion.
Potassium gluconate	Adults: 40-60 mmol/day PO in divided doses Children: Not established for routine pediatric use — individualize under pediatric/nephrology-directed weight-based dosing.	Unpleasant taste and aftertaste; nausea, heartburn	Avoid combining with a potassium-sparing diuretic without frequent monitoring	An alternative oral salt, useful in patients with concurrent acidosis.

Potassium-Sparing Diuretics

Used for increased kidney potassium losses (e.g., hyperaldosteronism, concomitant use of other diuretics); also useful for magnesium conservation. The most frequent and serious side effect of every agent in this class is hyperkalemia — avoid in kidney or adrenal insufficiency, older adults, patients with diabetes, and patients already taking another potassium-raising drug (see Risk Factors).

Drug	Dosage	Adverse effects	Drug interactions	Comments
Amiloride	Adults: 5-20 mg/day PO Children: Not established for routine pediatric use — individualize under pediatric/nephrology-directed weight-based dosing.	Hyperkalemia; muscle cramps; headache; GI symptoms (uncommon)	Avoid combining with NSAIDs, ACE inhibitors, ARBs, or potassium supplements — risk of severe hyperkalemia
Spironolactone	Adults: 25-200 mg/day PO in single or divided doses; up to 400 mg/day in hyperaldosteronism Children: Not established for routine pediatric use — individualize under pediatric/nephrology-directed weight-based dosing.	Hyperkalemia; gynecomastia, breast tenderness; androgen-like side effects; GI symptoms	Avoid combining with NSAIDs, ACE inhibitors, ARBs, or potassium supplements — risk of severe hyperkalemia	Steroidal mineralocorticoid receptor antagonist; use for primary or secondary hyperaldosteronism.
Eplerenone	Adults: 25-50 mg/day PO Children: Not established for routine pediatric use — individualize under pediatric/nephrology-directed weight-based dosing.	Hyperkalemia; dizziness, headache; rise in serum creatinine	Avoid combining with NSAIDs, ACE inhibitors, ARBs, or potassium supplements — risk of severe hyperkalemia	More selective for the mineralocorticoid receptor than spironolactone — less gynecomastia/breast tenderness.
Finerenone	Adults: Per current dosing guidance for its approved indication Children: Not established for routine pediatric use — individualize under pediatric/nephrology-directed weight-based dosing.	Hyperkalemia	Avoid combining with NSAIDs, ACE inhibitors, ARBs, or potassium supplements — risk of severe hyperkalemia	Non-steroidal mineralocorticoid receptor antagonist — an effective alternative to the steroidal agents above.
Triamterene / hydrochlorothiazide	Adults: Per current combination-product dosing guidance Children: Not established for routine pediatric use — individualize under pediatric/nephrology-directed weight-based dosing.	Hyperkalemia; photosensitivity; electrolyte disturbance from the thiazide component	Avoid combining with NSAIDs, ACE inhibitors, ARBs, or potassium supplements — risk of severe hyperkalemia	Triamterene is available only in combination with hydrochlorothiazide in Canada — there is no single-ingredient triamterene product.

References

Potassium homeostasis and management of dyskalemia in kidney diseases: conclusions from a Kidney Disease: Improving Global Outcomes (KDIGO) Controversies Conference — Kidney International (Clase CM, Carrero JJ, Ellison DH, et al.; KDIGO Conference Participants). Kidney Int 2020;97(1):42-61
Potassium Disorders: Hypokalemia and Hyperkalemia — American Family Physician (Kim MJ, Valerio C, Knobloch GK). Am Fam Physician 2023;107(1):59-70
Spurious hyperkalaemia — BMJ (Smellie WS). BMJ 2007;334(7595):693-695
Clinical Management of Hyperkalemia — Mayo Clinic Proceedings (Palmer BF, Carrero JJ, Clegg DJ, et al.). Mayo Clin Proc 2021;96(3):744-762
Pharmacological Interventions for the Acute Treatment of Hyperkalaemia: A Systematic Review and Meta-analysis — Resuscitation (Jessen MK, Andersen LW, Djakow J, et al.; ILCOR Advanced Life Support Task Force). Resuscitation 2025;208:110489
Sodium Zirconium Cyclosilicate for Urgent Therapy of Severe Hyperkalemia — New England Journal of Medicine (Kosiborod M, Peacock WF, Packham DK). N Engl J Med 2015;372(16):1577-1578
Sodium Zirconium Cyclosilicate in Hyperkalemia — New England Journal of Medicine (Packham DK, Rasmussen HS, Lavin PT, et al.). N Engl J Med 2015;372(3):222-231
Patiromer in Patients with Kidney Disease and Hyperkalemia Receiving RAAS Inhibitors — New England Journal of Medicine (Weir MR, Bakris GL, Bushinsky DA, et al.; OPAL-HK Investigators). N Engl J Med 2015;372(3):211-221
Efficacy and safety of potassium infusion therapy in hypokalemic critically ill patients — Critical Care Medicine (Hamill RJ, Robinson LM, Wexler HR, Fox AW). Crit Care Med 1991;19(5):694-699
Hypokalemia — New England Journal of Medicine (Gennari FJ). N Engl J Med 1998;339(7):451-458

Professional reference only. Apply clinical judgment and verify patient-specific decisions against current authoritative guidance and product information.