Sodium Thiosulfate

Sodium thiosulfate significantly reduces the side effects of cisplatin, a cancer medication, and is also used for the emergency treatment of cyanide poisoning.

Overview

Sodium thiosulfate, when administered in combination with the cancer medication cisplatin, can significantly reduce the side effects of cisplatin, including renal damage and hearing loss.

In addition to counteracting the side effects of cisplatin, sodium thiosulfate can be used as treatment in emergency situations of cyanide poisoning, subsequent to the administration of sodium nitrate. Cyanide poisoning results from either inhalation or ingestion of cyanide, which then bonds to the mitochondria of red blood cells, prohibiting the electron transport to oxygen. This renders the oxygen useless to the body and results in asphyxiation. Treatment with sodium nitrate first creates methemoglobinemia which removes the cyanide from the mitochondria. Subsequent treatment with the sodium thiosulfate then bonds to the now free cyanide, creating a nontoxic thiocyanate.

Conditions treated:

  • Counteract cisplatin induced hearing loss
  • Counteract cisplatin induced renal damage
  • Counteract cyanide poisoning

Type of Medicine:

  • Antidote
  • Chemical

Side Effects:

Although side effects do not occur in all patients who are administered sodium thiosulfate, side effects have been reported by some patients. The most common side effect by patients injected with sodium thiosulfate is abnormally low blood pressure. A less frequent but still severe side effect noticed by a small amount of patients is the increased risk of bleeding. Other less frequent and less severe side effects include but are not limited to: confusion, nausea, overheating, headaches, loss or reduction of taste, and vomiting. If any of these side effects are experienced, medical attention should be sought.

Dosage:

As should be done for all medications, only the prescribed dosage by the presiding physician should be dispensed and taken, and any directions on the label should be heeded. Different dosages will be prescribed to different patients with different conditions, so following the instructed dosage is crucial. Patients should also discontinue medication when advised to do so by their physician, regardless of any supply that may be remaining.

The amount of medication taken and the frequency for which it is taken depends on the strength of the medication and the patient information. General injection dosage guidelines from the manufacturer for different applications do exist. It is worth reiterating that the general injection dosage guidelines from the manufacturer may differ from the prescribed dosage from the physician, and when in doubt, the prescribed dosage and frequency from the physician should be observed. The physician, unlike the manufacturer, is able to factor more specific information about the patient and will use that information to create an appropriate treatment plan.

For adults and teenagers taking cisplatin, the first dose of sodium thiosulfate (typically 4 grams per square meter of body surface), is usually injected directly into a vein prior to the administration of the dose of cisplatin. The second dose can be administered simultaneous to the cancer medication and is injected into a vein at 12 grams per square meter over six hours.

For cyanide poisoning in adults and teenagers, a usual dose consists of 12.5 grams injected directly into a vein at a rate of 0.625 to 1.25 grams per minute. For the treatment of cyanide poisoning in children, the dosage is lower and dependent on the size of the child, consisting of 412.5 milligrams per kilogram of body weight. The rate at which the sodium thiosulfate is injected, however, remains the same: 0.625 to 1.25 grams per minute.

Overdosing on sodium thiosulfate can produce additional side effects that should be flagged with a physician. These side effects from overdosing can include but are not limited to agitation, blurred vision, hallucinations, mental changes, muscle cramps, nausea, vomiting, pain in the joints, and ringing in the ears. If a patient experiences any signs or symptoms associated with an overdose, they need immediate attention. Either call 911 or the Poison Control Center (1-800-222-1222) immediately.

Major Drug Interactions:

Some medications, when used in combination, may change the desired effects of each of the medications being administered. The interaction between medications may render a medication ineffective in treatment or cause dangerous reactions. Because of this, patients should keep a list of the current medications that are being taken at any given time in order to inform the presiding physician. This list should include the name of the medication, type of medication, dosage rate and frequency, and should include prescribed medications as well as any non-prescribed medications, like over-the-counter medications. Over-the-counter medications could also interact or interfere with the medications being prescribed. Using this information, the physician can choose to not prescribe a medication, change a dosage or take other necessary precautions based on any existing or known interactions.

Due to a lack of formal clinical drug interaction studies conducted with sodium thiosulfate injections, no major drug interactions are noted at this time.

In addition, any patient suffering from any of the following medical problems should also inform their physician prior to the administration of sodium thiosulfate, as sodium thiosulfate may cause the symptoms of these conditions, or the conditions themselves, to worsen.

  • Edema (swelling of feet or lower legs)
  • Heart disease
  • High blood pressure (hypertension)
  • Kidney disease
  • Liver disease
  • Toxemia of pregnancy

Note: Sodium thiosulfate may cause the body to retain water, which may cause the condition of toxemia in pregnancy to worsen.

Warnings:

Sodium thiosulfate may contain trace impurities of sodium sulfate, but this should not discourage administering the drug for emergency situations, regardless of whether the patient is sulfite-sensitive.

Clinical Studies on the safety and efficacy of administering sodium thiosulfate, as well as any negative side effects, have not been performed on certain demographics. There have been no formal studies, other than animal studies, on the effects to pregnant women or the fetuses and no conclusions have been drawn from those studies to insinuate any significant negative risks. It is also not known if sodium thiosulfate is excreted in human breast milk, but there is no data to assume that breastfeeding may be safely started again following the administration of sodium thiosulfate. If there is any doubt in administering sodium thiosulfate to a pregnant or breastfeeding woman, contact a knowledgeable physician. In emergency situations, the potential benefit from administering the sodium thiosulfate outweighs any potential negative risks.

In the case of administering sodium thiosulfate to children, there are no reports or clinical studies to evaluate the efficacy or safety. The dosage recommendations for children above are based on theoretical calculations from the extrapolation from animal studies, the antidote detoxifying potential, and a small number of human case reports.

Geriatric patients or patients with impaired or decreased renal functionality should exercise caution in taking sodium thiosulfate, as a substantial amount of sodium thiosulfate is already excreted from the kidneys. Additional sodium thiosulfate in the body may alter or worsen renal functionality in these patients. If sodium thiosulfate is prescribed, it may be useful to monitor the renal functions of the patient to ensure toxic reactions are not occurring.

Due to a lack of any adequate and controlled studies in some demographics, sodium thiosulfate should only be used in emergency situations. However, in emergency situations, the benefit of the administration of sodium thiosulfate outweighs the potential risks.

Storage

Sodium thiosulfate is supplied in 50 milliliter vials and should be stored at a controlled room temperature, between 20 and 25 degrees Celsius. Excursions from this temperature are permitted for short periods of time in the range of 15 to 30 degrees Celsius. Sodium thiosulfate should be protected from direct sunlight and freezing.

Small amounts of sodium thiosulfate can be flushed down a sink with a large quantity of water, unless specific laws prohibit this disposal. Larger amounts of the drug should be stored for disposal according to federal, state and local regulations.

Summary

Sodium thiosulfate is used to decrease the side effects of the cancer medication cisplatin, including hearing loss and renal damage, as well as to treat emergency cyanide poisoning. While this drug is beneficial to have on-hand if cyanide is present or to be taken during treatment with cisplatin, there are many side effects to consider, as well as the possibility of overdosing. Major side effects include abnormally low blood pressure and increased risk of bleeding, with minor side effects including nausea, overheating, headaches, loss of taste, and vomiting. No significant drug interactions are known, but sodium thiosulfate can exacerbate impaired or decreased renal functionality, as well as edema, heart disease, hypertension, high blood pressure, liver disease, kidney disease, and toxemia of pregnancy. Consulting a physician prior to any administration of sodium thiosulfate is imperative, as the dosage and frequency will be altered based on conditions and patient information.

In the case of use in emergency cyanide poisoning, there is no alternative treatment. Sodium thiosulfate, along with sodium nitrate, should be administered quickly to revive the patient and prevent asphyxiation. The potential benefits of administering the drug, at specific this time, outweigh the potential risks and side effects.

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Last Reviewed:
December 23, 2017
Last Updated:
December 22, 2017
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