Pharm

Potassium Replacement

Potassium Replacement, Potassium Supplementation, Extended Release Potassium Chloride Tablet, Immediate-Release Potassium Chloride Powder, Potassium Bicarbonate Effervescent Tablet, K-Dur

See Also

Indications

Hypokalemia

Precautions

Magnesium Replacement is often needed in conjunction with Potassium
Adjust protocol for renal disease
1. Oliguria: Urine Output < 30 ml/hour
2. Renal Failure: Serum Creatinine > 3.0 mg/dl

Background

Expect 0.1 mEq increase in Serum Potassium for every 10 mEq Potassium administered

Preparations

Potassium Chloride
1. Potassium Chloride IV (see below)
2. Extended Release Potassium Chloride Tablets (preferred)
  1. Order generic Potassium chloride ER ($15 per month)
  2. Available as 8, 10, 15, 20 meq tablets
  3. K-DUR brand-name is not available in U.S. as of 2016
3. Immediate-Release Potassium Chloride Powder
  1. Expensive ($290 per month)
  2. Diluted in liquid and are less than palatable
  3. Better tolerated in divided dosing (20 mEq at a time)
  4. Indicated in patients with Feeding Tubes and those with Delayed Gastric Emptying
Potassium bicarbonate (or oral preparations with citrate or gluconate, or IV Potassium acetate)
1. Consider in Metabolic Acidosis with Hypokalemia
2. Potassium Bicarbonate Effervescent Tablet 25 mEq orally at 1-2 tabs (25 to 50 mEq) per dose
3. Potassium bicarbonate is more palatable than Potassium chloride
Potassium phosphate (IV)
1. Most Dietary Potassium is in the form of Potassium phosphate
  1. However oral Potassium phosphate supplement doses are associated with Diarrhea
2. Indications: Hypokalemia with Hypophosphatemia
References
1. (2016) Presc Lett 23(4): 23

Management
Oral Potassium Replacement

Dietary Sources: Fruits and Vegetables
1. See Foods with High Potassium Content
2. May supply 40-60 meq/day
  1. However 40 meq is equivalent to 4 bananas which may be difficult to sustain
3. Dietary Potassium (Potassium phosphate) is less effective replacement than KCl
  1. Most Hypokalemia is associated with concurrent chloride depletion
Oral KCl 20-40 meq immediate release powder in water or juice or KCl extended release tablets
1. Powder has unpleasant taste (patients may prefer Swallowing tablets)
2. Serum Potassium < 3.0 mEq/L (total body deficit 200-300 meq)
  1. Give KCl 20 meq orally every 2 hours for 4 doses, then recheck level OR
  2. Give KCl 40 meq orally every 2 hours for 2 doses, then recheck level
  3. Typically continue Potassium Replacement at 20 meq twice daily for 4-5 days
3. Serum Potassium: 3.0 to 3.5 mEq/L (total body deficit 100-200 meq)
  1. Give KCl 20 mEq orally every 2 hours for 2 doses OR KCl 40 mEq once, then recheck level
  2. Typically continue Potassium Replacement at 20 meq twice daily for 2-3 days
Maintenance dosing
1. KCl 20 mEq orally daily when on Loop Diuretics or for Hyperaldosteronism

Management
IV Potassium Replacement

IV Preparations
1. Potassium Chloride (KCl) 10 meq IV "K bump"
2. Potassium Chloride (KCl) 20 meq use is limited to delivery via Central IV Access
IV Replacement Algorithm
1. Use 10 meq KCl IV in 50ml solution over 30 minutes minimum
  1. Dextrose containing IV solution not recommended
    1. Risk of Insulin induced exacerbation of Hypokalemia
  2. In select situations, may give up to 40 meq in 1 hr
  3. Example indication for faster delivery: DKA
  4. Cardiac monitoring if replacing >10 mEq per hour
  5. Recheck Serum Potassium after 30 mEq given
2. Serum Potassium < 3.0 mEq/L (total body deficit 200-300 meq)
  1. Give KCl 10 meq IV slowly every hour for 5 doses, then recheck level
3. Serum Potassium: 3.0 to 3.5 mEq/L (total body deficit 100-200 meq)
  1. Give KCl 10 meq IV slowly every hour for 3 doses, then recheck level

References

Hayes and Swaminathan in Herbert (2021) EM:Rap 21(5): 7-9
Kim (2023) Am Fam Physician 107(1): 59-70 [PubMed]
Viera (2015) Am Fam Physician 92(6): 487-95 [PubMed]