Sodium Bicarbonate

Usage

• Medical Conditions: Sodium bicarbonate is prescribed for various medical conditions, including metabolic acidosis (a condition where there is too much acid in the body fluids), indigestion, and heartburn. It is also used to alkalinize the urine, which can be helpful in certain medical conditions and with some medications. In emergency medicine and critical care settings, it’s used to manage severe acidosis during cardiac arrest and other critical situations. It is used as an antacid to neutralize stomach acid and alleviate symptoms of heartburn, sour stomach, and acid indigestion.

• Pharmacological Classification: Systemic alkalinizing agent, antacid, electrolyte replenisher.

• Mechanism of Action: Sodium bicarbonate acts as a buffer, neutralizing excess acid in the blood and other body fluids. It works by directly reacting with acidic substances, converting them into less acidic forms. This helps maintain a balance of pH. Orally, it reacts with hydrochloric acid in the stomach to produce carbon dioxide and water, neutralizing stomach acid. Intravenously, it buffers excess hydrogen ions, increasing blood pH, and shifts potassium intracellularly.

Alternate Names

• Alternate Names: Baking soda, bicarbonate of soda, sodium hydrogen carbonate.

• Brand Names: Alka-Seltzer, Bell/ans.

How It Works

• Pharmacodynamics: Sodium bicarbonate increases blood pH by buffering excess hydrogen ions. It increases plasma bicarbonate and buffers excess hydrogen ion concentration, resulting in an increase in blood and urinary pH. This can have effects on various physiological processes.

• Pharmacokinetics:

  • Absorption: Orally administered sodium bicarbonate is rapidly absorbed from the gastrointestinal tract.
  • Metabolism: It is not metabolized but dissociates into sodium and bicarbonate ions.
  • Elimination: Primarily excreted by the kidneys as bicarbonate, increasing urinary pH.

• Mode of Action: Sodium bicarbonate neutralizes stomach acid by reacting with hydrochloric acid (HCl) to form sodium chloride (NaCl), carbon dioxide (CO2), and water (H2O).

• Receptor Binding/Enzyme Inhibition/Neurotransmitter Modulation: No specific receptor binding, enzyme inhibition, or neurotransmitter modulation.

• Elimination Pathways: Renal excretion.

Dosage

Standard Dosage

Adults:

• Oral: For indigestion and heartburn, 325 mg to 2 g, one to four times per day. For alkalinizing urine, an initial dose of 4 g, followed by 1-2 g every four hours, not exceeding 16 g daily.

Children:

• Oral: Dosage should be determined by a doctor for both indigestion and alkalinizing urine.

Special Cases:

• Elderly Patients: Start with lower doses and monitor closely for side effects.
• Patients with Renal Impairment: Dose reduction is often necessary; close monitoring is essential.
• Patients with Hepatic Dysfunction: Generally, no dose adjustment is needed, but monitor patients closely.
• Patients with Comorbid Conditions: Caution should be used in patients with heart failure, hypertension, or edema due to the sodium content.

Clinical Use Cases

• Intubation, Surgical Procedures, Mechanical Ventilation, ICU Use, Emergency Situations: IV administration; dosage varies depending on the severity of acidosis and clinical context. Dosing should be guided by blood gas analysis and electrolyte monitoring.

Dosage Adjustments

• Dose modifications based on patient-specific factors like renal/hepatic dysfunction and comorbidities are crucial for safe and effective therapy.

Side Effects

Common Side Effects

• Stomach cramps, gas, belching, and swelling in the feet or ankles.

Rare but Serious Side Effects

• Irregular heartbeat, muscle weakness or twitching, confusion, irritability, seizures.

Long-Term Effects

• Metabolic alkalosis (a shift toward alkaline in the body’s acid-base balance) with long-term or excessive use.

Adverse Drug Reactions (ADR)

• Severe metabolic alkalosis, hypernatremia (high sodium), and fluid overload with IV administration.

Contraindications

• Metabolic or respiratory alkalosis, hypocalcemia, hypochloremia, hypernatremia. Conditions where sodium intake should be restricted (e.g., heart failure, severe renal impairment, edema).

Drug Interactions

• Corticosteroids, medications that contain sodium (may increase sodium levels), certain medications for high blood pressure or inflammation, lithium, quinidine, amphetamines, aspirin, memantine.

Pregnancy and Breastfeeding

• Pregnancy Safety Category: C. While sodium bicarbonate can be used if the benefits outweigh the risks, alternative antacids are preferred due to the risk of fluid retention.
• Breastfeeding: Limited information available; generally considered safe for short-term use in typical doses.

Drug Profile Summary

• Mechanism of Action: Neutralizes acid in the stomach and body fluids.
• Side Effects: Stomach cramps, gas, belching, fluid retention, electrolyte imbalances.
• Contraindications: Alkalosis, hypocalcemia, hypernatremia, sodium-restricted diets.
• Drug Interactions: Corticosteroids, medications containing sodium, lithium.
• Pregnancy & Breastfeeding: Use with caution; alternative antacids are often preferred.
• Dosage: Varies depending on indication; see above for specifics.
• Monitoring Parameters: Serum electrolytes (sodium, potassium, chloride, bicarbonate), blood pH, blood gases.

Popular Combinations

• Often combined with other antacids in over-the-counter medications.

Precautions

• Use caution in patients with heart failure, edema, or renal impairment due to sodium load. Avoid extravasation during IV administration. Monitor for electrolyte imbalances.

FAQs (Frequently Asked Questions)

Q1: What is the recommended dosage for Sodium Bicarbonate?

A: Varies based on indication, age, and other factors. See the Dosage section for specific details.

Q2: How does Sodium Bicarbonate work in metabolic acidosis?

A: It buffers excess hydrogen ions, increasing blood pH.

Q3: What are the common side effects of Sodium Bicarbonate?

A: Stomach cramps, gas, and belching are common side effects.

Q4: Is Sodium Bicarbonate safe during pregnancy?

A: Use with caution; other antacids are generally preferred.

Q5: What are the contraindications of Sodium Bicarbonate?

A: Alkalosis, hypocalcemia, hypernatremia, conditions requiring sodium restriction.

Q6: Can Sodium Bicarbonate interact with other medications?

A: Yes, it can interact with several medications, including corticosteroids and lithium.

Q7: How should Sodium Bicarbonate be administered?

A: Available in oral and intravenous forms. The route depends on the clinical situation.

Q8: How is Sodium Bicarbonate dosed in children?

A: Pediatric dosing should be determined by a physician.

Q9: What are the monitoring parameters when administering IV Sodium Bicarbonate?

A: Monitor serum electrolytes, blood pH, and blood gases closely.

Q10: Is Sodium Bicarbonate safe for long-term use?

A: Long-term use can lead to metabolic alkalosis and should be monitored.