Which medications in the drug class Alkalinizing Agents are used in the treatment of Hyperkalemia?

Updated: Apr 09, 2020
  • Author: Eleanor Lederer, MD, FASN; Chief Editor: Vecihi Batuman, MD, FASN  more...
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Alkalinizing Agents

In patients with severe metabolic acidosis, sodium bicarbonate IV is used as a buffer that breaks down to water and carbon dioxide after binding free hydrogen ions. By increasing the pH, sodium bicarbonate promotes a temporary potassium shift from the extracellular to the intracellular environment. It also enhances the effectiveness of insulin in patients with acidemia. These agents have been successfully used in the treatment of acute overdose of slow-release oral potassium preparations.

The use of sodium bicarbonate can be considered in treatment of hyperkalemia even in the absence of metabolic acidosis, though it is less likely to be effective in this context. This agent also increases sodium delivery to the kidney, which assists in potassium excretion.

Sodium bicarbonate

The bicarbonate ion neutralizes hydrogen ions and raises urinary and blood pH. Onset of action occurs within minutes; duration of action is approximately 15-30 minutes. Monitor blood pH to avoid excess alkalosis. Use the 8.4% solution in adults and children and the 4.2% solution in children younger than 2 years. The adult dose for hyperkalemia is 50 mEq IV over 5 minutes. Consider methods of enhancing potassium removal or excretion, as appropriate.

The following formula may be used to estimate the dose that should be administered for metabolic acidosis:

HCO3− (mEq) = 0.5 (L/kg) × weight (kg) × (24 − serum HCO3− [mEq/L])

This formula has many limitations; however, it allows the practitioner to make a rough determination of the amount of bicarbonate required and subsequently to titrate against the pH and anion gap.

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