Thallium Acetate

(BAN, USAN, rINN)

💊 Chemical information

Talio, acetato de; Thallous Acetate.
Chemical formula: C2H3O2Tl = 263.4.
CAS — 7440-28-0 (thallium); 563-68-8 (thallium acetate); 7446-18-6 (thallium sulfate).

💊 Adverse Effects

Thallium salts are toxic when inhaled, ingested, or absorbed through the skin. Symptoms of poisoning may appear within 12 to 24 hours of a single toxic dose and include severe abdominal pain, nausea and vomiting, diarrhoea, gastrointestinal haemorrhage, salivation, metallic taste, paralytic ileus, pancreatic damage, and in severe cases cardiovascular collapse, tremors, delirium, convulsions, paralysis, and coma, leading to death in 1 to 2 days. However, the acute reaction may subside, to be followed within about 10 days by the development of neurological effects including paraesthesia, myalgia, myopathy, motor neuropathy, and visual disturbances due to optic neuropathy, psychosis, delirium, convulsions, and other signs of encephalopathy, tachycardia, hypertension, skin eruptions, and hepatorenal injury. Recovery from neurological damage is slow and may be incomplete. Alopecia occurs within 15 to 20 days; stomatitis may also develop. Death may result from respiratory failure; patients are also predisposed for several weeks to cardiac arrhythmias and sudden death. Fatalities have occurred after ingestion of 1 g or less in adults, although the UK Poisons Information Service consider the usual lethal dose by ingestion to be in the range 3 to 10 g in adults. Smaller repeated doses are also toxic, with symptoms appearing over several weeks. Constipation is a common feature of less severe poisoning.

Poisoning.

References.
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5. Tabandeh H, Thompson GM. Visual function in thallium toxicity. BMJ 1993; 307: 324
6. Questel F, et al. Thallium-contaminated heroin. Ann Intern Med 1996; 124: 616
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9. Misra UK, et al. Thallium poisoning: emphasis on early diagnosis and response to haemodialysis. Postgrad Med J 2003; 79: 103–5
10. Hoffman RS. Thallium toxicity and the role of Prussian blue in therapy. Toxicol Rev 2003; 22: 29–40
11. Thompson DF, Callen ED. Soluble or insoluble Prussian blue for radiocesium and thallium poisoning? Ann Pharmacother 2004; 38: 1509–14
12. Kuo H-C, et al. Acute painful neuropathy in thallium poisoning. Neurology 2005; 65: 302–4.

💊 Treatment of Adverse Effects

Gastric lavage should be considered if the patient presents within 1 hour of acute ingestion. Intensive supportive therapy is necessary. Attempts have been made to increase the faecal and urinary excretion of thallium. A suspension of activated charcoal has been given to reduce intestinal absorption and enteric recycling. Prussian blue given orally as a drink or via a nasogastric tube is also used routinely. A purgative such as mannitol may be required with either activated charcoal or Prussian blue as constipation is common in severe thallium toxicity. Giving potassium chloride by mouth may mobilise thallium from the tissues but is hazardous, especially if given during the early stage as signs of poisoning may be aggravated. Traditional chelation therapy is not generally recommended for thallium poisoning. Haemoperfusion, haemodialysis, or peritoneal dialysis have been reported to be effective in eliminating absorbed thallium, although clinical benefit is doubtful.

💊 Uses and Administration

Thallium acetate was formerly used by mouth for depilation in ringworm and as an ingredient of depilatory creams but both systemic and local treatments have caused deaths, and it is no longer used for such purposes. It has also been used as a rodenticide and insecticide; thallium sulfate has been used similarly. The use of thallium salts is strictly regulated in many countries. However, use in industry could still constitute a hazard. Cases of malicious poisoning still occur occasionally.
Published May 08, 2019.