Sodium Chloride Tablet Dosing for Hyponatremia
Standard Dosing Recommendation
For patients with mild to moderate hyponatremia (serum sodium 120-134 mmol/L) due to SIADH who fail fluid restriction alone, the recommended dose is 100 mEq (approximately 6 grams) of oral sodium chloride three times daily, totaling 18 grams per day. 1, 2
This dosing applies specifically to euvolemic hyponatremia (SIADH) as adjunctive therapy to fluid restriction of 1 L/day, not as monotherapy. 1
Critical Dosing Context by Clinical Scenario
When Salt Tablets Are Appropriate
SIADH (Euvolemic Hyponatremia): First-line treatment is fluid restriction to 1 L/day; if this fails after 24-48 hours, add oral sodium chloride 100 mEq three times daily. 3, 1, 2
Cerebral Salt Wasting: May use oral sodium supplementation as adjunct to volume repletion with isotonic saline, particularly in neurosurgical patients. 3, 2
When Salt Tablets Are Contraindicated
Hypervolemic hyponatremia (heart failure, cirrhosis): Salt tablets worsen fluid overload and edema—these patients require sodium restriction (2-2.5 g/day) and fluid restriction (1-1.5 L/day), not supplementation. 3, 1
Severe symptomatic hyponatremia with altered mental status, seizures, or coma: Requires immediate 3% hypertonic saline IV, not oral tablets. 3, 2
Severe renal failure: Impaired sodium handling makes oral tablets inappropriate. 3
Practical Administration Details
Conversion: 1 teaspoon of table salt contains approximately 2,300 mg (100 mEq) of sodium. 1
Each 1 gram of sodium chloride contains approximately 17 mEq of sodium. 3
Home preparation is NOT recommended due to formulation errors that can cause dangerous sodium swings. 1
Commercial sodium chloride tablets (typically 1 gram each) should be used—patients would take 6 tablets three times daily to achieve 100 mEq per dose. 1
Critical Safety Parameters
Maximum Correction Rates
Standard patients: Never exceed 8 mmol/L correction in 24 hours to prevent osmotic demyelination syndrome. 3, 1, 2
High-risk patients (cirrhosis, alcoholism, malnutrition, prior encephalopathy): Limit to 4-6 mmol/L per day, maximum 8 mmol/L in 24 hours. 3, 1, 2
Severe symptomatic cases: Correct 6 mmol/L over first 6 hours or until symptoms resolve, but total must not exceed 8 mmol/L in 24 hours. 1, 2
Monitoring Protocol
Initial phase: Check serum sodium every 4 hours when starting salt tablets. 1, 2
Once stable: Transition to daily monitoring. 1
Watch for: Hyperkalemia (especially with renal impairment), fluid overload, hypertension. 3, 2
Pediatric Dosing (Special Population)
For infants and children with chronic kidney disease stages 3-5 and polyuric salt-wasting:
Dose range: 1-5 mmol Na/kg body weight/day. 1
Average studied dose: 3.2 ± 1.04 mmol/kg/day. 1
Infants on peritoneal dialysis: Consider sodium supplementation for all due to substantial losses. 1
Alternative Formulations
FDA-Approved Oral Solution
Sodium Chloride Oral Solution 23.4% (4 mEq/ml):
Adult dose (ages 9-50): 4 ml (equivalent to 936 mg sodium chloride, providing 368 mg elemental sodium). 4
Children under 9 and adults over 50: Consult physician for individualized dosing. 4
This provides approximately 16 mEq of sodium per 4 ml dose, requiring multiple doses to reach the 100 mEq target. 4
Common Pitfalls to Avoid
Never use salt tablets as monotherapy in SIADH—always combine with fluid restriction to 1 L/day. 1
Never use in hypervolemic states—this includes heart failure and cirrhosis patients who need sodium restriction, not supplementation. 3, 1
Never exceed 8 mmol/L correction in 24 hours—overcorrection causes irreversible osmotic demyelination syndrome. 3, 1, 2
Never rely on physical exam alone to determine volume status—sensitivity is only 41.1% and specificity 80%. 3
Avoid potassium-containing salt substitutes—patients are at risk for hyperkalemia. 3
Evidence for Efficacy
Oral sodium chloride tablets have been shown effective in selected patients with severe hyponatremia when IV access is limited, providing graded and predictable increases in serum sodium when dosed hourly at calculated rates. 5 In heart failure patients with hyponatremia, supplemental sodium chloride (via salted vegetables or IV 3% saline) rapidly corrected hyponatremia without causing heart failure exacerbation or hypernatremia. 6
However, IV sodium chloride was associated with significantly better outcomes than fluid restriction alone in postmenopausal women with chronic symptomatic hyponatremia, particularly when administered before respiratory insufficiency developed. 7