What over-the-counter antacids are mostly sodium bicarbonate?

Over-the-Counter Antacids Containing Sodium Bicarbonate

Sodium bicarbonate (650 mg/tablet) is available as an over-the-counter antacid in its pure form, commonly known as baking soda. 1

Available Sodium Bicarbonate Antacid Products

• Pure sodium bicarbonate tablets: 650 mg (10 grain) tablets sold as antacids
• Combination products: Some antacid formulations contain sodium bicarbonate mixed with other ingredients

Benefits of Sodium Bicarbonate as an Antacid

Sodium bicarbonate works as an antacid by:

• Neutralizing stomach acid
• Providing rapid relief of acid-related symptoms
• Buffering gastric pH effectively 2

Clinical Applications in Acid-Related Conditions

Sodium bicarbonate is used in clinical settings for:

1. Neutralizing acid in gastric reflux
2. Buffering local anesthetics to decrease injection pain 2
3. Treatment of sodium channel blocker poisoning 2

Important Considerations and Precautions

Potential Adverse Effects

• Metabolic alkalosis: Excessive use can cause severe metabolic alkalosis 3
• Fluid retention: High sodium content may lead to fluid retention in susceptible individuals 4
• Electrolyte disturbances: Can cause hypokalemia and hypernatremia 4, 3
• Acid rebound: May cause increased acid production after initial neutralization

Contraindications

Sodium bicarbonate antacids should be used with caution in patients with:

• Hypertension
• Heart failure
• Renal impairment
• Sodium-restricted diets
• History of kidney stones 4

Medication Interactions

• Can enhance absorption of certain medications:
  • Some NSAIDs (tolfenamic acid, mefenamic acid, ibuprofen)
  • Sulphonylurea antidiabetic agents (glipizide, glibenclamide, tolbutamide)
  • Oral anticoagulants like dicoumarol 5

Clinical Pearls

1. Sodium bicarbonate antacids provide rapid relief but should not be used regularly for chronic conditions
2. Patients should be advised not to exceed recommended dosages
3. Alternative antacids containing calcium carbonate, magnesium hydroxide, or aluminum hydroxide may be preferable for regular use
4. Combination antacids containing both aluminum hydroxide and magnesium hydroxide provide balanced acid neutralization with fewer side effects 4

Special Populations

• Patients with heart failure: Should avoid sodium bicarbonate antacids due to sodium content
• Patients with kidney disease: Should use with caution due to risk of metabolic alkalosis
• Hypertensive patients: Should consider alternative antacids with lower sodium content

While sodium bicarbonate is effective for short-term acid neutralization, its high sodium content and potential for metabolic derangements make it less suitable for regular or long-term use compared to other available antacid formulations.