What medications can help excrete potassium or decrease potassium levels in patients with hyperkalemia, especially those with cardiac conditions or impaired renal function?

Medications That Excrete or Decrease Potassium Levels

Loop and thiazide diuretics are the primary medications that promote urinary potassium excretion, with loop diuretics (furosemide 40-80 mg daily) being the most effective first-line agents for patients with adequate kidney function. 1, 2

Primary Potassium-Excreting Medications

Loop Diuretics

• Furosemide 40-80 mg IV or oral daily is the preferred agent for enhancing renal potassium excretion in patients with adequate kidney function (eGFR >30 mL/min) 1, 2
• Loop diuretics promote urinary potassium excretion by stimulating flow and delivery of potassium to the renal collecting ducts 2
• These agents should be titrated to maintain euvolemia, not primarily for potassium management 2
• Loop diuretics work within hours and are particularly effective when combined with sodium bicarbonate in patients with concurrent metabolic acidosis 2

Thiazide Diuretics

• Hydrochlorothiazide causes hypokalemia through increased urinary potassium losses, especially with brisk diuresis 3
• Thiazide diuretics promote urinary potassium excretion by increasing distal sodium delivery 2
• Hypokalemia may develop especially during concomitant use of corticosteroids or ACTH, or after prolonged therapy 3
• Periodic determination of serum electrolytes is essential, as clinically significant hypokalemia has been consistently observed, particularly at doses >12.5 mg 3

Mineralocorticoid Agents

• Fludrocortisone increases potassium excretion but carries significant risks of fluid retention, hypertension, and vascular injury 2
• This agent should be used cautiously and only when other options are exhausted 2

Newer Potassium-Binding Agents (Remove Potassium via GI Tract)

Sodium Zirconium Cyclosilicate (SZC/Lokelma)

• SZC 10 g three times daily for 48 hours, then 5-15 g once daily for maintenance is the fastest-acting potassium binder 1, 2
• Onset of action is approximately 1 hour, making it suitable for urgent outpatient scenarios 1, 2
• SZC reduces serum potassium within 1 hour of a single 10-g dose and is effective for both acute hyperkalemia (≥5.8 mEq/L) and chronic management 1
• For hemodialysis patients, start with 5 g once daily on non-dialysis days, adjusting weekly in 5 g increments based on predialysis potassium 2
• Monitor for edema due to sodium content 2

Patiromer (Veltassa)

• Patiromer 8.4 g once daily with food, titrated up to 25.2 g daily based on potassium response 1, 2
• Onset of action is approximately 7 hours, with mean potassium reduction of 0.65 mEq/L at 4 weeks 2
• Must be separated from other oral medications by at least 3 hours to avoid reduced absorption 2
• Binds potassium in exchange for calcium in the colon, increasing fecal excretion 2
• Monitor magnesium levels closely, as patiromer causes hypomagnesemia—for each 1 mEq/L increase in serum magnesium, serum potassium increases by 1.07 mEq/L 2
• Superior safety profile compared to sodium polystyrene sulfonate, with no risk of colonic necrosis 2

Acute Potassium-Shifting Agents (Temporary Measures)

Insulin with Glucose

• Regular insulin 10 units IV with 25 g dextrose shifts potassium intracellularly within 15-30 minutes, lasting 4-6 hours 1, 2, 4
• Can be repeated every 4-6 hours as needed, with careful monitoring of serum potassium and glucose levels 1
• Always administer glucose with insulin to prevent life-threatening hypoglycemia 2
• Patients with low baseline glucose, no diabetes history, female sex, and altered renal function are at higher risk of hypoglycemia 1

Beta-2 Agonists

• Nebulized albuterol 10-20 mg in 4 mL as adjunctive therapy for shifting potassium intracellularly 1, 2
• Effects begin within 15-30 minutes but last only 2-4 hours 1, 2
• Should be given together with insulin for maximum effect 2

Sodium Bicarbonate

• Sodium bicarbonate 50 mEq IV over 5 minutes ONLY if metabolic acidosis is present (pH <7.35, bicarbonate <22 mEq/L) 1, 2
• Promotes potassium excretion through increased distal sodium delivery and counters acidosis-induced potassium release 1, 2
• Effects take 30-60 minutes to manifest 1, 2
• Do not use without metabolic acidosis—it is ineffective and wastes time 1, 2

Hemodialysis (Most Effective Removal Method)

• Hemodialysis is the most reliable and effective method for potassium removal, especially in severe cases unresponsive to medical management, oliguria, or end-stage renal disease 2
• Reserved for severe hyperkalemia (>6.5 mEq/L) with ECG changes, refractory cases, or patients with severe renal impairment 1, 2
• Potassium levels can rebound 4-6 hours post-dialysis as intracellular potassium redistributes 2
• Consider adjusting dialysate potassium concentration (typically 2.0-3.0 mEq/L) based on predialysis levels 2

Critical Algorithm for Medication Selection

For acute severe hyperkalemia (>6.5 mEq/L or ECG changes):

1. IV calcium gluconate 15-30 mL of 10% solution first (cardiac protection, does NOT lower potassium) 2
2. Give all three shifting agents together: insulin + glucose, nebulized albuterol, and sodium bicarbonate (only if acidotic) 2
3. Loop diuretics if adequate renal function OR hemodialysis if renal failure 2

For chronic hyperkalemia management (5.0-6.5 mEq/L):

1. Loop diuretics (furosemide 40-80 mg daily) if eGFR >30 mL/min 1, 2
2. Initiate potassium binder (SZC or patiromer) to enable continuation of life-saving RAAS inhibitors 1, 2
3. Never permanently discontinue RAAS inhibitors—use dose reduction plus potassium binders instead 1, 2

Common Pitfalls to Avoid

• Never use sodium polystyrene sulfonate (Kayexalate)—it has delayed onset, limited efficacy, and risk of bowel necrosis and intestinal ischemia 1, 2
• Remember that calcium, insulin, and beta-agonists do NOT remove potassium from the body—they only temporize for 30-60 minutes to 4-6 hours 1, 2
• Never give insulin without glucose—hypoglycemia can be life-threatening 2
• Never use sodium bicarbonate without metabolic acidosis—it is ineffective in non-acidotic patients 1, 2
• Loop diuretics are ineffective in advanced renal failure (eGFR <30 mL/min)—dialysis is required 2
• Thiazide diuretics can cause severe hypokalemia, especially with corticosteroids or ACTH—monitor electrolytes periodically 3

Monitoring Requirements

• Check potassium within 1 week of starting or adjusting diuretics or potassium binders 1, 2
• Monitor magnesium levels in patients on patiromer to detect hypomagnesemia 2
• Recheck potassium every 2-4 hours after acute interventions 1
• For patients on RAAS inhibitors, reassess potassium 7-10 days after dose changes 1, 2