Sodium chloride - Drug Monograph

Introduction

Sodium chloride, commonly known as table salt, is an essential electrolyte and pharmaceutical agent with critical physiological and therapeutic roles. As a medication, it is primarily used in various formulations for fluid replacement, electrolyte correction, and as a vehicle for other medications. Pharmaceutical-grade sodium chloride is available in multiple concentrations for intravenous, subcutaneous, oral, and topical administration.

Mechanism of Action

Sodium chloride functions as an electrolyte replenisher and osmotic agent. Sodium is the major cation of extracellular fluid and plays a critical role in maintaining fluid distribution, osmotic pressure, and acid-base balance. Chloride, the major extracellular anion, follows sodium changes to maintain electroneutrality. When administered intravenously, sodium chloride increases plasma osmolality, resulting in fluid shifts from intracellular to extracellular compartments.

Indications

• Treatment and prevention of sodium chloride deficiencies (hyponatremia)
• Fluid resuscitation in hypovolemic states
• As a diluent for compatible medications
• Maintenance of patency in intravenous lines
• Irrigation of body cavities, wounds, and surgical sites
• Inhalation therapy for sputum induction
• Oral rehydration therapy

Dosage and Administration

• 0.9% (isotonic): 1-2 L initially, then adjust based on clinical response
• 3% and 5% (hypertonic): Reserved for severe hyponatremia with neurological symptoms; administer cautiously with frequent monitoring

• Pediatric: Dose based on weight and electrolyte requirements
• Geriatric: Use with caution due to increased risk of fluid overload
• Renal impairment: Adjust dose based on electrolyte monitoring
• Hepatic impairment: Monitor for fluid retention and electrolyte imbalances

Pharmacokinetics

• Absorption: Well-absorbed from GI tract; completely bioavailable when administered IV
• Distribution: Distributed throughout extracellular fluid
• Metabolism: Not metabolized; functions as an electrolyte
• Elimination: Primarily renal excretion; small amounts lost in sweat and feces
• Half-life: Not applicable (electrolyte)

Contraindications

• Hypernatremia
• Fluid retention states
• Congestive heart failure
• Renal impairment with sodium retention
• Hypersensitivity to sodium chloride or any component of the formulation

Warnings and Precautions

• Use with caution in patients with heart failure, renal impairment, or cirrhosis
• Risk of hypernatremia with excessive administration
• Potential for fluid overload and pulmonary edema
• Monitor serum sodium and chloride concentrations regularly
• Hypertonic solutions may cause vein damage and tissue necrosis if extravasation occurs

Drug Interactions

• Corticosteroids: May enhance sodium-retaining effects
• Lithium: Sodium chloride may alter lithium excretion
• Diuretics: May affect electrolyte balance
• ACE inhibitors: May impair sodium excretion

Adverse Effects

• Fluid overload
• Hypernatremia
• Hyperchloremic acidosis
• Injection site reactions

• Pulmonary edema
• Congestive heart failure
• Severe electrolyte imbalances
• Cerebral edema (with rapid correction of hyponatremia)

Monitoring Parameters

• Serum sodium and chloride levels
• Fluid balance (intake/output)
• Body weight
• Vital signs (especially blood pressure and respiratory rate)
• Neurological status (when correcting hyponatremia)
• Signs of fluid overload (edema, crackles, JVD)

Patient Education

• Report signs of fluid overload (swelling, shortness of breath, rapid weight gain)
• Understand the purpose of sodium chloride administration
• Follow prescribed dietary sodium restrictions if applicable
• Report any injection site pain or swelling
• Keep follow-up appointments for electrolyte monitoring

References

1. Lexicomp Online. Sodium Chloride: Drug Information. Wolters Kluwer Clinical Drug Information, Inc. 2. Micromedex Solutions. Sodium Chloride. IBM Watson Health. 3. National Center for Biotechnology Information. PubChem Compound Summary for CID 5234, Sodium Chloride. 4. American Society of Health-System Pharmacists. AHFS Drug Information. 5. Clinical Pharmacology [Internet]. Sodium Chloride. Gold Standard, Inc. 6. FDA prescribing information for various sodium chloride formulations