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Indications

Sodium Thiosulfate is a simple salt with two quite different uses. In Bangladesh it is widely sold as tablets for fish and shrimp ponds, where it is used to treat the water: it neutralises chlorine and some toxic gases and helps fish recover from stress caused by poor water quality. In hospitals, an injectable form is used as an antidote for cyanide poisoning (usually together with Sodium Nitrite) and, in some cases, to protect hearing during certain cancer treatment or to treat calcium deposits under the skin (calciphylaxis). The tablets sold for ponds are not for human use.

How It Works

In water, Sodium Thiosulfate reacts with chlorine and similar chemicals and turns them into harmless substances. In the body, it gives sulfur to an enzyme that converts cyanide into thiocyanate, a much less toxic substance that leaves the body in the urine.

Dosage and Administration

Pond tablets: use only as directed on the label or by a fisheries or aquaculture adviser. The amount depends on the pond area and water depth, and tablets are usually spread evenly over the water. Hospital injection: given slowly into a vein by a doctor or nurse; the dose is decided by the doctor according to the patient's condition.

Interactions

In ponds, do not mix with other chemicals or disinfectants at the same time unless advised, as it can neutralise them. As a medicine, it is given by health professionals who will check other treatments; there are few known drug interactions.

Contraindications

The injection should not be used in people with a known allergy to it. Pond products must not be swallowed or used as a human medicine.

Side Effects

The injection may cause low blood pressure, nausea, vomiting, headache, a salty taste, warmth and changes in blood salts. Pond tablets may irritate the skin and eyes if handled without care.

Get urgent medical help if pond tablets are swallowed, if a person feels faint, has trouble breathing, chest pain or swelling of the face after an injection, or if there are signs of an allergic reaction.

Pregnancy and Lactation

In a hospital emergency such as cyanide poisoning, the doctor may give it in pregnancy if the benefit outweighs the risk. Pregnant or breastfeeding women handling pond tablets should wear gloves and avoid contact with dust.

Precautions and Warnings

Wear gloves when handling pond tablets, wash hands afterwards and keep them away from food. Do not overdose a pond, as large amounts can lower oxygen in the water. For the injection, doctors take extra care in people with heart or kidney problems or those on a low-salt diet, because it contains a lot of sodium.

Overdose

In ponds, too much may cause oxygen loss; increase aeration and seek advice. In people, a large dose may cause vomiting, low blood pressure and salt imbalance and needs medical care.

Therapeutic Class

Antidote (cyanide poisoning); water treatment agent for aquaculture.

Storage

Store below 30°C in a dry place, away from light and out of the reach of children. Hospital injections are stored as directed on the pack.