Sodium Chloride: Comprehensive Medication Profile

Classification

Sodium chloride is an electrolyte replacement agent and osmotic therapeutic used to correct sodium deficits, manage fluid balance, and treat specific cardiac arrhythmias caused by sodium channel blockade. 1

Mechanism of Action

Sodium chloride dissociates into sodium (Na+) and chloride (Cl-) ions in solution, directly increasing extracellular sodium concentration and plasma osmolality. 2
Sodium ions are the principal cations of extracellular fluid and control water distribution, fluid balance, and osmotic pressure across cellular membranes. 1
In sodium channel blocker toxicity (tricyclic antidepressants, antiarrhythmics), sodium administration increases extracellular sodium concentration to overcome channel blockade and reverse conduction slowing. 2
The mechanism involves providing substrate to compete at blocked cardiac sodium channels, shortening QRS duration and reversing cardioversion-resistant ventricular tachycardia. 2

Effects on the Heart

Sodium chloride administration can reverse life-threatening cardiac conduction abnormalities caused by sodium channel blocking drugs, including QRS prolongation, ventricular tachycardia, and Brugada-like ECG patterns. 2

Therapeutic Cardiac Effects:

Reverses conduction slowing in sodium channel blocker toxicity (Class IIb recommendation). 2
Shortens QRS duration in tricyclic antidepressant overdose when given as NaCl or NaHCO3 boluses. 2
Treats ventricular tachycardia that becomes more frequent or difficult to cardiovert in patients taking sodium channel blockers. 2

Adverse Cardiac Effects:

Excessive parenteral sodium chloride may precipitate congestive heart failure and acute pulmonary edema, especially in patients with cardiovascular disease. 1
Rapid administration can cause edema and clinical findings resembling congestive heart failure. 1
Patients receiving corticosteroids or drugs causing sodium retention face amplified risk. 1

Effects on Other Body Systems

Renal System:

Patients with impaired renal function are particularly vulnerable to adverse effects from sodium chloride administration. 1
Excessive sodium can cause oliguria and increased blood urea nitrogen. 1

Fluid and Electrolyte Balance:

Excessive sodium chloride causes hypopotassemia and acidosis. 1
Signs of postoperative salt intolerance include cellular dehydration, weakness, disorientation, anorexia, nausea, distention, and deep respiration. 1
Can cause hypernatremia with confusion, seizures, and cardiovascular instability if improperly dosed. 3

Metabolic Effects:

Increases plasma osmolality and can reduce intracranial pressure in cerebral herniation. 4
Affects water distribution across all body compartments. 1

Indications

Primary Indications:

Sodium channel blocker toxicity causing ventricular tachycardia (more frequent or cardioversion-resistant). 2
Tricyclic antidepressant overdose with QRS prolongation. 2
High intestinal stomal output (1200-2000 mL daily or more) requiring sodium supplementation. 3
Salt-wasting chronic kidney disease in pediatric patients. 3
Syndrome of inappropriate antidiuresis (SIAD) with hyponatremia. 5, 6, 7
Cerebral herniation and elevated intracranial pressure (23.4% solution). 4

Supplemental Indications:

Electrolyte replacement in parenteral fluid therapy. 1
Hydration strategies for athletes (hyperhydration protocols). 8

Route and Dosage

Intravenous Administration:

For Sodium Channel Blocker Toxicity:

Administer sodium bolus (as NaCl or NaHCO3) for ventricular tachycardia. 2
Specific dosing not standardized in guidelines; titrate to clinical effect and QRS narrowing. 2

For Cerebral Herniation (23.4% NaCl):

Can be administered via peripheral or central venous access safely. 4
Typical dose range based on institutional protocols; median ICP reduction of 13-24 mm Hg achieved. 4

For Electrolyte Replacement (23.4% solution):

Determine milliequivalents needed, divide by four to calculate milliliters required. 1
Withdraw volume aseptically and dilute in appropriate IV solutions (e.g., 5% Dextrose). 1
Administer diluted solution intravenously. 1

For Streptomycin Administration (when IM not tolerated):

Dilute to 12-15 mg in 100 mL of 0.9% sodium chloride. 2
Must infuse over 30-60 minutes to avoid neuromuscular blockade. 2

For Extravasation Management:

Phentolamine 0.1-0.2 mg/kg (up to 10 mg) diluted in 10 mL of 0.9% sodium chloride injected intradermally at extravasation site. 2

Oral Administration:

For High Stomal Output:

Standard capsules contain 500 mg each. 3
Patients may require 14 capsules per 24 hours (7000 mg total). 3
Capsules can be opened and sprinkled on food or mixed with liquids for patients unable to swallow intact capsules. 3

For Pediatric Salt-Wasting CKD:

Typical supplementation: 1-5 mmol Na/kg body weight/day, adjusted by blood biochemistry. 3

For SIAD-Related Hyponatremia:

3 g/day oral NaCl tablets combined with fluid restriction. 6
Hourly oral NaCl calculated to deliver equivalent of 0.5 mL/kg/h of 3% NaCl for severe cases. 7

For Hyperhydration (Athletes):

7.5 tablets (1 g each) per liter of solution over 60 minutes. 8
Total fluid intake approximately 30 mL/kg fat-free mass. 8

Enteral Feeding:

Add salt to enteral feeds targeting sodium concentration of 100 mmol/L while maintaining osmolality near 300 mosmol/kg. 3

Titration Parameters

For Sodium Channel Blocker Toxicity:

Monitor continuous ECG for QRS narrowing (target <120 ms). 2
Assess frequency and ease of cardioversion for ventricular tachycardia. 2
Monitor serum potassium (maintain >4 mEq/L). 2

For Cerebral Herniation:

Monitor intracranial pressure (target reduction of 10-24 mm Hg). 4
Track cerebral perfusion pressure (target augmentation of 15-16 mm Hg). 4
Monitor mean arterial pressure (maintain ≥65 mm Hg). 4

For Hyponatremia:

Target serum sodium increase of 6 mEq/L over initial treatment period, not exceeding 8-10 mEq/L in 24 hours to avoid osmotic demyelination. 7
Monitor serum sodium every 2-4 hours during acute correction. 7

For Chronic Supplementation:

Monitor serum sodium, chloride, bicarbonate, and creatinine regularly. 3, 6
Adjust dose based on blood biochemistry and clinical response. 3

Contraindications and Precautions

Absolute Contraindications:

Patients with severe renal disease (relative contraindication requiring dose adjustment). 2, 1
Hypernatremia or fluid overload states. 1

Precautions:

Cardiovascular disease: Risk of precipitating congestive heart failure and acute pulmonary edema. 1
Impaired renal function: Adverse effects particularly likely to develop. 1
Patients receiving corticosteroids, corticotropin, or drugs causing sodium retention. 1
Pregnancy: Use only if clearly needed (no adequate animal studies). 1
Nursing mothers: Unknown if excreted in human milk; exercise caution. 1

Critical Safety Warnings:

Never use table salt as substitute for pharmaceutical sodium chloride capsules due to risk of dangerous hypo- or hypernatremia from formulation errors. 3
Concentrated solutions must be properly diluted to avoid hypernatremia. 3
23.4% NaCl has osmolarity of 8008 mOsm/L; monitor for extravasation. 4

Hold Parameters

Hold or reduce sodium chloride administration if:

Signs of fluid overload develop (peripheral edema, pulmonary crackles, elevated jugular venous pressure). 1
Serum sodium exceeds target or rises too rapidly (>8-10 mEq/L per 24 hours). 7
Signs of congestive heart failure emerge (dyspnea, orthopnea, S3 gallop). 1
Acute kidney injury develops (rising creatinine, oliguria). 6
Hypernatremia symptoms appear (confusion, seizures, altered mental status). 3
Mean arterial pressure falls below 65 mm Hg. 4

Adverse Reactions and Side Effects

Common Adverse Effects:

Edema and clinical findings resembling congestive heart failure from excessive administration. 1
Cellular dehydration, weakness, disorientation. 1
Anorexia, nausea, abdominal distention. 1
Deep respiration (compensatory for metabolic acidosis). 1

Serious Adverse Effects:

Acute pulmonary edema in patients with cardiovascular disease. 1
Hypopotassemia requiring potassium supplementation. 1
Metabolic acidosis. 1
Oliguria and increased blood urea nitrogen. 1
Acute kidney injury (especially when combined with furosemide). 6

Rare Complications:

Osmotic demyelination syndrome if sodium corrected too rapidly. 4, 7
Hemolysis (with hypertonic solutions). 4
Soft tissue injury from extravasation (theoretical risk with 23.4% solution, though not documented in one study). 4

Drug Interactions

Synergistic Effects:

Beta blockers: Used successfully in combination for sodium channel blocker toxicity. 2
Furosemide: Combined with NaCl for SIAD treatment, though increases risk of acute kidney injury and hypokalemia. 6

Antagonistic/Problematic Interactions:

Corticosteroids and corticotropin: Increase sodium retention, amplifying risk of fluid overload. 1
Drugs causing sodium retention: Increased risk of congestive heart failure. 1
ACE inhibitors/ARBs with potassium-sparing diuretics: May cause severe hyperkalemia if sodium supplementation includes potassium. 2

Monitoring Requirements with Interactions:

When combined with furosemide, monitor for hypokalemia (potassium ≤3.0 mmol/L) and acute kidney injury. 6
With diuretics, monitor electrolytes shortly after initiating therapy and periodically thereafter. 2

Assessment, Monitoring, and Desired Outcomes

Pre-Administration Assessment:

Obtain baseline serum sodium, potassium, chloride, bicarbonate, creatinine, and hemoglobin. 4, 6
Assess cardiovascular status (heart failure signs, blood pressure, jugular venous pressure). 1
Evaluate renal function (creatinine, urine output). 1
For cardiac toxicity: Obtain 12-lead ECG measuring QRS duration. 2
Inspect parenteral solutions for particulate matter and discoloration before administration. 1

Ongoing Monitoring: