From the FDA Drug Label
If the serum potassium level is greater than 2.5 mEq/liter, potassium can be given at a rate not to exceed 10 mEq/hour in a concentration of up to 40 mEq/liter. The 24-hour total dose should not exceed 200 mEq. If urgent treatment is indicated (serum potassium level less than 2.0 mEq/liter with electrocardiographic changes and/or muscle paralysis) potassium chloride may be infused very cautiously at a rate of up to 40 mEq/hour.
The approach to replenishing potassium in inpatient cases of hypokalemia involves:
- Monitoring serum potassium levels and adjusting the dose accordingly
- Administering potassium chloride at a rate not to exceed 10 mEq/hour for serum potassium levels greater than 2.5 mEq/liter
- Urgent treatment with a rate of up to 40 mEq/hour for serum potassium levels less than 2.0 mEq/liter with electrocardiographic changes and/or muscle paralysis
- Continuous cardiac monitoring in critical cases 1
- Guiding potassium therapy primarily by serial electrocardiograms, especially in patients receiving digitalis 1
From the Research
Inpatient hypokalemia should be managed with oral potassium chloride (KCl) supplementation as the first line of treatment, with the dose and route of administration determined by the severity of the deficiency, as recommended by the most recent study 2. The approach to replenishing potassium in inpatient cases of hypokalemia involves assessing the severity of the deficiency and choosing the appropriate route and dose of potassium supplementation.
- For mild hypokalemia (3.0-3.5 mEq/L), oral potassium chloride (KCl) at 40-60 mEq/day divided into 2-3 doses is recommended.
- For moderate hypokalemia (2.5-3.0 mEq/L), 60-80 mEq/day of oral KCl is appropriate.
- In severe cases (<2.5 mEq/L) or when patients cannot take oral medications, intravenous (IV) potassium is necessary, with a maximum rate of 10-20 mEq/hour through a peripheral vein, and concentrations not exceeding 40 mEq/L to avoid phlebitis, as suggested by 3. The underlying cause of hypokalemia should be addressed simultaneously, and magnesium levels should also be checked and corrected if low, as hypomagnesemia can make potassium repletion difficult, as noted in 4. Additionally, potassium phosphate may be preferred in patients with hypophosphatemia, while potassium bicarbonate or citrate is better for those with metabolic acidosis, as discussed in 5. It is essential to monitor serum potassium levels every 4-6 hours during aggressive repletion to minimize the risks of overcorrection, which can lead to dangerous hyperkalemia and cardiac arrhythmias, as highlighted in 6.