1. Clinical Overview
Sodium Bicarbonate (34mg/ml) is an intravenous (IV) solution of a systemic alkalizer and electrolyte replenisher. It is a sterile, non-pyrogenic, hypertonic solution primarily used for the correction of metabolic acidosis and as a urinary alkalinizer. In the Indian context, it is a critical drug in emergency medicine, nephrology, and critical care settings, often used to manage acidosis secondary to conditions like diabetic ketoacidosis, renal failure, and severe sepsis.
| Onset | Duration | Bioavailability |
|---|---|---|
| Immediate upon intravenous administration. | Variable, depends on the underlying acid-base status and renal function; effect on blood pH can last for several hours. | 100% for intravenous route. |
2. Mechanism of Action
Sodium bicarbonate dissociates in plasma to provide sodium (Na+) and bicarbonate (HCO3-) ions. The bicarbonate ion is a component of the body's primary extracellular buffer system (HCO3-/H2CO3). It combines with excess hydrogen ions (H+) to form carbonic acid (H2CO3), which rapidly dissociates into water (H2O) and carbon dioxide (CO2). The CO2 is then exhaled via the lungs. This reaction shifts the blood pH towards alkalinity, correcting metabolic acidosis.
3. Indications & Uses
- Correction of documented metabolic acidosis (e.g., in diabetic ketoacidosis, lactic acidosis, renal tubular acidosis)
- Severe diarrhea with bicarbonate loss
- Cardiopulmonary resuscitation (CPR) to correct acidosis in prolonged arrest, though use is now more selective
- Urinary alkalinization to enhance excretion of certain drugs (e.g., salicylates, barbiturates) in overdose
4. Dosage & Administration
Adult Dosage: Dose is highly individualized based on arterial blood gas (ABG) or serum bicarbonate levels. General guideline: 1-2 mEq/kg (approx. 50-100 mEq) IV over 1-2 hours initially. Further doses based on repeat ABG. For CPR: 1 mEq/kg IV bolus, repeated every 10 minutes if arrest is prolonged.
Administration: For 34mg/ml (8.1%) solution: MUST be diluted before IV administration. Typically diluted in 5% Dextrose or 0.9% Sodium Chloride. Administer via a large-bore IV line in a large vein (e.g., antecubital) to minimize risk of tissue irritation and necrosis. Infusion rate should not exceed 1 mEq/kg/hour in routine correction. In emergencies (CPR), can be given as a slow IV push over 1-2 minutes.
5. Side Effects
Common side effects may include:
- Local: Irritation at injection site, phlebitis
- Metabolic: Metabolic alkalosis (with overuse), hypokalemia, hypernatremia
6. Drug Interactions
| Drug | Effect | Severity |
|---|---|---|
| Potassium-Sparing Diuretics (e.g., Spironolactone, Amiloride) | Increased risk of hyperkalemia, especially in renal impairment. | Major |
| Corticosteroids (e.g., Prednisolone, Hydrocortisone) | Increased risk of sodium and fluid retention, edema, and hypertension. | Moderate |
| Lithium | Increased renal excretion of lithium, decreasing its serum levels and efficacy. | Moderate |
| Methotrexate | Urinary alkalinization can reduce renal clearance of methotrexate, potentially increasing toxicity. | Moderate |
| Quinidine, Flecainide | Urinary alkalinization decreases renal excretion, increasing their plasma levels and risk of toxicity. | Moderate |
| Salicylates (Aspirin) | Urinary alkalinization increases renal excretion of salicylates, used therapeutically in overdose. | Moderate (Therapeutic) |
7. Patient Counselling
- This medication will be administered by a healthcare professional in a hospital/clinic setting.
- Inform your doctor about all other medications you are taking, including supplements.
- Report any swelling in hands/feet, difficulty breathing, severe headache, or muscle twitching immediately.
8. Toxicology & Storage
Overdose: Symptoms of severe metabolic alkalosis: irritability, neuromuscular excitability, tetany, confusion, hypokalemia symptoms (muscle weakness, arrhythmias), hypernatremia symptoms (thirst, fever, tachycardia), and fluid overload (edema, pulmonary rales).
Storage: Store at room temperature (15-25°C). Protect from freezing and excessive heat. Do not use if the solution is discolored or contains particulate matter. The container is for single use only. Discard any unused portion. Keep out of reach of children.