Oral Sodium Chloride (Salt Tablets) for Hyponatremia
Oral sodium chloride tablets may be considered for persistent hyponatremia that is severe and unresolving, after correction of the underlying cause and with appropriate volume assessment. [1] In the Royal Cornwall Hospitals NHS Trust guideline, the medication is specified as “Slow Na 2 tablets QDS” when adequate salt intake is required. [1]
Medication Selection Algorithm
Oral salt tablets are considered when hyponatremia is persistent despite initial cause-directed therapy and fluid restriction is insufficient or not sustainable. [1]
Treatment Initiation Thresholds
Oral salt tablets may be considered in non-critical patients when hyponatremia is severe and remains unresolving. [1] Severely symptomatic hyponatremia requires hypertonic saline rather than oral salt tablets. [1], [2]
Salt Tablet Dosage Regimen
In the Royal Cornwall Hospitals NHS Trust guideline, “Slow Na” is dosed as:
- Slow Na 2 tablets QDS (4 times daily). [1] Each “Slow Sodium” tablet contains 600 mg sodium chloride. [3] Each Slow Sodium tablet contains approximately 10 mEq of Na+. [3]
Monitoring and Correction Limits
After hypertonic or other active correction strategies, sodium rise should be limited to reduce osmotic demyelination syndrome risk. [1], [2] The Royal Cornwall Hospitals NHS Trust guideline states sodium levels must not increase by more than 8–10 mmol/L in 24 hours and 18 mmol/L in 48 hours. [1] Endotext describes limiting the increase in plasma sodium to no more than 10 mmol/L in the first 24 hours and no more than 8 mmol/L per day thereafter. [2]
Common Pitfalls to Avoid
Oral salt tablets should not be used as monotherapy for severe acute symptomatic hyponatremia when rapid correction is required. [1], [2] Sodium correction limits should be observed to reduce the risk of osmotic demyelination syndrome. [1], [2]
Treatment Goals
The immediate treatment goal in severe symptomatic hyponatremia is improvement of symptoms or a controlled rise in serum sodium, not normalization. [1], [2] Hypertonic therapy should be stopped when the clinical target is reached or when a sodium concentration threshold is reached, whichever occurs first. [2]