What the label lists and what reports show
Sodium thiosulfate side effects
Sodium thiosulfate's FDA label: “Most common adverse reactions are: Hypotension, headache, disorientation ( 6 ) To report SUSPECTED ADVERSE REACTIONS, contact Hope Pharmaceuticals at 1-800-755-9595 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch.” FAERS holds 540 reports naming it through July 30, 2026; the reaction reported most often, leaving out the conditions it is used for, product-use terms and outcomes, is calciphylaxis (86 reports).
- No generic listed
Check it at the source: the sodium thiosulfate FDA label on DailyMed (effective May 26, 2026, Hope Pharmaceuticals); the FDA FAERS public dashboard.
What does the label list?
From the label: adverse reactionsMost common adverse reactions are: Hypotension, headache, disorientation ( 6 ) To report SUSPECTED ADVERSE REACTIONS, contact Hope Pharmaceuticals at 1-800-755-9595 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch.
Table 3. Adverse Reactions (≥10%) in Patients Who Received PEDMARK and Cisplatin with a Difference Between Arms of >5% Compared to Cisplatin Alone in SIOPEL 6
This table is printed in the PEDMARK label published by Fennec Pharmaceuticals Inc. of October 27, 2025; the label quoted above does not print one.
| Reaction | All Grades (%) | Grade 3 or 4 (%) | All Grades (%) | Grade 3 or 4 (%) |
|---|---|---|---|---|
| Vomiting | 85 | 8 | 54 | 3.6 |
| Nausea | 40 | 3.8 | 30 | 5 |
| Decreased Hemoglobin | 34 | 19 | 29 | 16 |
| Hypernatremia | 26 | 1.9 | 3.6 | 0 |
| Hypokalemia | 15 | 9 | 1.8 | 0 |
| Hypophosphatemia | 15 | 9 | 1.8 | 0 |
| Hypermagnesemia | 11 | 9 | 5 | 3.6 |
| Pyrexia | 15 | 0 | 9 | 0 |
Rows and numbers as the label prints them, under its own column headings (the first rows of a longer table where it runs on). A reaction in a trial table is not necessarily caused by the medicine, and trials differ from everyday use.
From the label: adverse reactions, continuedThere have been no controlled clinical trials conducted to systematically assess the adverse events profile of sodium thiosulfate. The medical literature has reported the following adverse events in association with sodium thiosulfate administration. These adverse events were not reported in the context of controlled trials or with consistent monitoring and reporting methodologies for adverse events. Therefore, frequency of occurrence of these adverse events cannot be assessed. Cardiovascular system: hypotension Central nervous system: headache, disorientation Gastrointestinal system: nausea, vomiting Hematological: prolonged bleeding time Body as a Whole: salty taste in mouth, warm sensation over body In humans, rapid administration of concentrated solutions or solutions not freshly prepared, and administration of large doses of sodium thiosulfate have been associated with a higher incidence of nausea and vomiting. However, administration of 0.1 g sodium thiosulfate per pound up to a maximum of 15 g in a 10-15% solution over 10-15 minutes was associated with nausea and vomiting in 7 of 26 patients without concomitant cyanide intoxication. In a series of 11 human subjects, a single intravenous infusion of 50 mL of 50% sodium thiosulfate was associated with increases in clotting time 1-3 days after administration. …
Source: FDA drug label, Hope Pharmaceuticals, effective May 26, 2026 (SPL set 82f55408-2de9-463d-85e8-b39c3b259f0b), via openFDA; the full label on DailyMed
What do FAERS reports show?
540 reports list sodium thiosulfate among the medicines taken, each a report of something that happened, not proof the medicine caused it; 78 are coded as a death and 189 as a hospital stay. Counts follow how widely a medicine is used and watched, and they are not a measure of how risky it is. Of the 21 reactions below, 4 are named by the same term (in US spelling) in the label's adverse reactions, warnings or patient leaflet; a reaction the label does not name may still be there under another word, and a report does not show that the medicine caused it.
Reports received each year
The 25 most reported reactions
Source: FDA Adverse Event Reporting System (FAERS) via openFDA, reports through July 30, 2026; reactions as MedDRA preferred terms
What next?
- Sodium thiosulfate: the full record
- label, generics, price, shortages, recalls
- Report a side effect to the FDA
- MedWatch
- Side effects hub
- the most reported medicines and reactions