What is the recommended dosage and administration protocol for Sodium Thiosulfate in hemodialysis patients?

Sodium Thiosulfate Prescription for Hemodialysis Patients

Standard Dosing Protocol

For hemodialysis patients requiring sodium thiosulfate for vascular calcification, prescribe 12.5-25 grams intravenously administered 2-3 times per week immediately following each hemodialysis session for 3-6 months. 1

Specific Prescription Details

Route and Timing:

• Administer intravenously after completing the hemodialysis session 1, 2
• Never administer via the same IV line as hydroxocobalamin due to chemical incompatibility 3
• Infuse over 30-60 minutes to minimize adverse effects 4, 5

Dosing Recommendations:

• Standard dose: 25 grams per session, 3 times weekly (post-hemodialysis) 1, 2, 4
• Lower dose option: 12.5 grams per session if concerned about adverse effects 1, 6
• Preparation: Dilute in 100-800 mL of 5% dextrose or normal saline 5
• Duration: Continue for 3-6 months, then reassess based on clinical response 1, 6

Dosing Adjustments Based on Dialysis Intensity

The dose must be adjusted based on your patient's specific hemodialysis prescription, as more intensive dialysis removes more sodium thiosulfate and requires higher weekly doses. 2

• Standard 3x/week HD (12 hours/week): 25 g per session (75 g/week total) 2, 4
• More frequent HD (4-6x/week, 16-24 hours/week): Increase to 72-100 g/week divided across sessions 2
• Less frequent HD (2x/week): Reduce proportionally but monitor closely 2
• High-flux dialyzers with higher blood/dialysate flows: May require dose increases up to 245 g/week for very intensive regimens 2

Pediatric Dosing

For children and young adults: 25 g/1.73 m² body surface area per hemodialysis session 7

Critical Monitoring Requirements

Monitor the following parameters throughout treatment:

• Blood pressure: Must be monitored during each infusion 3
• Serum calcium: Check before each session; adjust dialysate calcium concentration if hypocalcemia develops (prolonged QT interval risk) 7
• Anion gap: Monitor for metabolic acidosis, which commonly develops but is generally well-tolerated 4
• Bone mineral density: Significant hip bone density decline can occur with higher doses; consider DEXA scanning at baseline and 6 months 1
• Clinical wound healing: Assess lesions monthly for improvement 6, 4, 7

Common Adverse Effects and Management

Expect and counsel patients about:

• Nausea and vomiting: Most common, occurs in majority of patients; consider antiemetics 6, 4
• Metabolic acidosis with elevated anion gap: Usually mild and does not require treatment discontinuation 4
• Hypocalcemia: Increase dialysate calcium concentration from 2.5 to 3.0 mEq/L if symptomatic 7
• Gastrointestinal disturbances: Dose-dependent; consider dose reduction if severe 1

Critical Pitfalls to Avoid

Do not use the 50 mL (12.5 gram) dose intended for cyanide poisoning as your calciphylaxis dose—this is a common error. The cyanide antidote dose is given as a single emergency dose, while calciphylaxis requires chronic dosing at 12.5-25 grams per session. 3

Do not prescribe sodium thiosulfate without simultaneously:

• Discontinuing vitamin D analogs (calcitriol, paricalcitol) 7
• Switching to non-calcium-based phosphate binders 7
• Using low-calcium dialysate (2.0-2.5 mEq/L) 7
• Ensuring adequate wound debridement for calciphylaxis lesions 4

Do not continue treatment indefinitely without reassessment—while some patients require 34+ months of therapy, most show clinical response within 3-6 months, and bone density concerns necessitate periodic risk-benefit evaluation. 1, 4

Sample Prescription Format

Rx: Sodium Thiosulfate Injection 12.5 g/50 mL (250 mg/mL)

• Dose: 25 grams (two 50 mL vials) IV
• Dilute in 100 mL normal saline or 5% dextrose
• Infuse over 60 minutes
• Administer immediately after each hemodialysis session
• Frequency: Three times weekly (Monday/Wednesday/Friday or Tuesday/Thursday/Saturday)
• Duration: 3-6 months, then reassess
• Dispense: 24 vials (4-week supply for 3x/week dosing)
• Refills: 2

Special instructions: Monitor blood pressure during infusion. Do not administer through same IV line as hydroxocobalamin. Notify prescriber if severe nausea, vomiting, or muscle cramps develop.