1. Clinical Overview
Sodium Chloride 0.75% w/v is a sterile, isotonic, or slightly hypertonic solution of sodium chloride in water for injection. It is an essential electrolyte replenisher and a fundamental component of extracellular fluid. In the Indian context, it is widely used as a nasal irrigation solution, wound cleansing agent, and for ophthalmic procedures. Its 0.75% concentration is specifically formulated to be more compatible with the physiological osmolarity of nasal mucosa (approx. 0.9% is isotonic to plasma) and is often preferred for nasal hygiene to reduce stinging and improve patient compliance.
| Onset | Duration | Bioavailability |
|---|---|---|
| Immediate upon contact with mucosal surfaces or tissues. | Transient; depends on the volume and site of administration. Electrolyte effects are integrated into body fluid compartments within minutes to hours. | 100% for systemic absorption when administered intravenously. For topical/nasal use, systemic absorption is negligible. |
2. Mechanism of Action
Sodium Chloride provides essential sodium (Na+) and chloride (Cl-) ions, which are the principal cations and anions of the extracellular fluid. As a 0.75% solution, it exerts a gentle osmotic effect. When used for nasal irrigation, it helps to liquefy viscous mucus, moisten the nasal mucosa, and flush out allergens, irritants, and infectious debris mechanically. It does not have a pharmacological decongestant action but relieves congestion by clearing obstructing secretions.
3. Indications & Uses
- Nasal irrigation for relief from nasal congestion due to allergic rhinitis (hay fever), sinusitis, and common cold
- Cleansing of minor wounds, abrasions, and burns
- Ophthalmic use as an eye wash for irritation or to remove loose foreign material (when formulated for ophthalmic use)
4. Dosage & Administration
Adult Dosage: Nasal Spray/Irrigation: 2-3 sprays into each nostril, 3-6 times daily or as needed. For irrigation with bulb syringe/neti pot: 100-250 mL per nostril, 1-2 times daily. Wound Cleansing: Apply sufficient quantity to irrigate and clean the area.
Administration: For Nasal Spray: Tilt head slightly forward. Insert tip into nostril, spray while breathing gently through the nose. Avoid deep inhalation. For Irrigation: Use sterile, lukewarm solution. Tilt head over basin, pour solution gently into one nostril allowing it to drain from the other. Do not use tap water for irrigation unless boiled and cooled. For Wounds: Use sterile solution. Pour or spray over wound. Pat dry surrounding skin.
5. Side Effects
Common side effects may include:
- Nasal use: Mild, transient stinging or burning sensation (less common with 0.75% vs. higher concentrations)
- Nasal irritation
- Sneezing
- Mild taste in the back of the throat.
6. Drug Interactions
| Drug | Effect | Severity |
|---|---|---|
| Corticosteroids (e.g., Fluticasone, Mometasone Nasal Spray) | Sodium Chloride irrigation prior to steroid spray may improve nasal delivery and efficacy by clearing mucus. | Minor |
| Lithium | Increased sodium intake may reduce lithium reabsorption in renal tubules, potentially decreasing lithium levels and efficacy. Monitor lithium levels. | Moderate |
| NSAIDs (e.g., Ibuprofen, Diclofenac), ACE Inhibitors (e.g., Ramipril) | Concurrent use in patients with renal impairment may increase risk of hyperkalemia or reduced renal function. Sodium chloride can affect fluid balance. | Moderate |
7. Patient Counselling
- DO use the solution as directed, ensuring device (spray bottle, neti pot) is clean.
- DO use sterile, distilled, boiled & cooled, or filtered water for preparing irrigation solutions if using a neti pot.
- DO discard any unused solution from an opened container after the recommended period (usually 24 hours for multi-dose vials).
- DO NOT share nasal spray bottles or irrigation devices with others.
- DO NOT use if the solution appears cloudy or contains particles.
- DO NOT sniff forcefully after administration.
8. Toxicology & Storage
Overdose: Topical/Nasal: Overdose is unlikely. Systemic overdose (from ingestion or inappropriate IV use) leads to hypernatremia: thirst, restlessness, dry mucous membranes, flushed skin, oliguria, tachycardia, hypertension, pulmonary edema, fever, confusion, seizures, coma.
Storage: Store below 30°C. Protect from direct sunlight and freezing. Keep the container tightly closed when not in use to maintain sterility. For multi-dose containers, check the label for the 'in-use' shelf life after opening (typically 24-28 days). Keep out of reach of children.