1. Clinical Overview
Sodium Chloride 3% is a sterile, non-pyrogenic, hypertonic saline solution for intravenous infusion. It contains 30 mg/mL (3 g/100 mL) of sodium chloride, providing approximately 513 mEq/L of sodium and chloride ions. It is an essential electrolyte replenisher and osmotic agent used to correct severe hyponatremia and manage cerebral edema. In the Indian context, it is a critical hospital-based therapy, often prepared in-house by hospital pharmacies or available as ready-to-use infusions from major manufacturers.
| Onset | Duration | Bioavailability |
|---|---|---|
| Immediate upon intravenous administration; osmotic effects on serum sodium begin within minutes. | Duration is variable and depends on the rate of infusion, total dose administered, and patient's renal function and fluid balance. Osmotic effects can last for several hours post-infusion. | 100% (Administered intravenously). |
2. Mechanism of Action
Sodium Chloride 3% exerts its therapeutic effects through its hypertonicity. When infused intravenously, it increases the osmolality of the extracellular fluid (ECF). This creates an osmotic gradient that draws water from the intracellular fluid (ICF) compartment into the ECF compartment. This mechanism is utilized to: 1) Raise serum sodium concentration in hyponatremia, and 2) Reduce intracranial pressure (ICP) by dehydrating brain cells, thereby reducing cerebral edema.
3. Indications & Uses
- Symptomatic Severe Hyponatremia (e.g., with seizures, altered mental status)
- Management of Cerebral Edema (especially in traumatic brain injury, cerebral hemorrhage, hepatic encephalopathy)
- Hyponatremic Encephalopathy
4. Dosage & Administration
Adult Dosage: Dosage is HIGHLY INDIVIDUALIZED based on serum sodium levels, symptoms, and correction goals. A common initial regimen for severe symptomatic hyponatremia: 1-2 mL/kg/hour (approx. 0.5-1 mL/kg of 3% NaCl) as an IV infusion. Typical total dose ranges from 100 mL to 500 mL over 24 hours. Goal: Increase serum sodium by 4-6 mEq/L in the first 4-6 hours, not exceeding 10-12 mEq/L in the first 24 hours.
Administration: MUST be administered via a large-bore peripheral IV or central venous catheter (preferred for concentrated solutions to avoid phlebitis). Use an infusion pump for precise control. NEVER administer as a rapid IV bolus unless in a life-threatening situation (e.g., active seizures). Incompatible with many drugs; do not mix with other medications in the same line unless compatibility is verified. Monitor serum sodium every 2-4 hours during infusion.
5. Side Effects
Common side effects may include:
- Infusion site reactions: pain, phlebitis, irritation
- Thirst
- Headache
- Nausea
6. Drug Interactions
| Drug | Effect | Severity |
|---|---|---|
| Corticosteroids (e.g., Prednisone, Hydrocortisone) | Concurrent use promotes sodium retention and potassium loss, increasing risk of hypernatremia, hypokalemia, and edema. | Major |
| Lithium | Increased sodium levels can reduce lithium clearance, potentially leading to lithium toxicity. Monitor lithium levels closely. | Major |
| Loop Diuretics (e.g., Furosemide) | May be used therapeutically together to enhance free water clearance in hyponatremia. However, can also exacerbate electrolyte imbalances (K+, Mg2+ loss). | Moderate |
| NSAIDs (e.g., Ibuprofen, Diclofenac) | May reduce renal sodium and water excretion, increasing risk of hypernatremia and fluid overload. | Moderate |
| ACE Inhibitors (e.g., Enalapril) / ARBs (e.g., Losartan) | May impair aldosterone-mediated sodium reabsorption, potentially altering response to hypertonic saline. Monitor blood pressure and sodium. | Moderate |
7. Patient Counselling
- DO report any severe headache, shortness of breath, chest pain, or swelling in limbs immediately.
- DO inform all doctors about this infusion if presenting to a new hospital.
- DONT consume extra salt or salty foods during treatment unless advised by your doctor.
- DONT stop or adjust the infusion rate yourself.
8. Toxicology & Storage
Overdose: Symptoms of overdose are those of hypernatremia and volume overload: Intense thirst, fever, nausea/vomiting, restlessness, confusion, neuromuscular excitability, seizures, coma, pulmonary edema, hypertension, tachycardia, oliguria, and death. The most feared complication of therapeutic use (not classic overdose) is Osmotic Demyelination Syndrome.
Storage: Store at room temperature (not exceeding 30°C). Protect from freezing and direct sunlight. Do not use if the solution is cloudy, contains particulate matter, or if the container is leaking or damaged. For single use only. Discard any unused portion. Keep out of reach of children.