Alka-Seltzer (sodium bicarbonate)

Medically Reviewed on 4/5/2022

Brand Name: Alka-Seltzer

Generic Name: sodium bicarbonate

Drug Class: Alkalinizing agents

What is Alka-Seltzer, and what is it used for?

Alka-Seltzer Heartburn Relief (sodium bicarbonate) is an oral medication and alkalinizing agent (antacid) that reduces stomach acid. It is a commonly used antacid to treat occasional episodes of heartburn, acid ingestion, and upset stomach.

How does Alka-Seltzer work?

  • Oral sodium bicarbonate provides rapid relief (within 15 minutes) of heartburn symptoms and should only be used to provide temporary relief of occasional episodes of stomach acid problems.
  • Oral administration of sodium bicarbonate results in the neutralization of hydrochloric acid in the stomach (raises blood and urinary pH) and the formation of sodium chloride, carbon dioxide, and water.

Do I need a prescription for Alka-Seltzer (sodium bicarbonate)?


What are the side effects of Alka-Seltzer?

Known side effects include:

What is the dosage for Alka-Seltzer?

  • Oral antacid: 325 mg to 2 g 1-4 times per day.

Which drugs interact with Alka-Seltzer?

Is Alka-Seltzer safe to use during pregnancy or while breastfeeding?

  • Sodium bicarbonate has not been adequately evaluated in pregnant women. Sodium bicarbonate has the potential risk of causing metabolic alkalosis and fluid overload in pregnancy. Therefore, sodium bicarbonate containing antacids are considered unsafe in pregnancy.
  • Sodium bicarbonate enters breast milk. Other antacids such as calcium carbonate or magnesium hydroxide are generally preferred over sodium carbonate due to their wider safety margin.

What else should I know about Alka-Seltzer?

What preparations of Alka-Seltzer are available?
  • Effervescent granules for oral solution: 460 mg. Oral tablet: 325 and 650 mg
How should I keep Alka-Seltzer stored?
  • Store at room temperature 59 C - 86 C (15 F – 30 F).


Digestive Disorders: Common Misconceptions See Slideshow


Alka-Seltzer Heartburn Relief (sodium bicarbonate) is an alkalinizing agent (antacid medication) used to reduce stomach acid and treat occasional episodes of heartburn, acid ingestion, and upset stomach. Side effects of Alka-Seltzer include belching, flatulence (gas), stomach pain, and edema (water retention). Alka-Seltzer is not recommended to treat heartburn during pregnancy or while breastfeeding an infant.

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Medically Reviewed on 4/5/2022
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