Fluoroacetate, also known as compound 1080, sodium monofluoroacetate (SMFA), and sodium fluoroacetate, is one of the most toxic substances known. In the past, it was used primarily as a rodenticide by licensed pest control companies, but it largely has been removed from the US market because of its hazardous nature. Compound 1080 use is currently restricted to livestock protection collars designed to protect sheep and cattle from coyotes. Occasionally, unlicensed product may be encountered. It is also still used commonly in Australia and New Zealand for vertebrate pest control. It is a tasteless, odorless water-soluble white crystalline powder. Fluoroacetamide (compound 1081) is a similar compound with similar toxicity.
Mechanism of toxicity
Fluoroacetate is metabolized to the toxic compound fluorocitrate, which blocks cellular metabolism by inhibiting the aconitase enzyme within the Krebs cycle. Clinical effects of poisoning are delayed (from 30 minutes to several hours) until fluoroacetate is metabolized to fluorocitrate.
Pharmacokinetics. The onset of effect is reported to be 30 minutes to several hours after ingestion. The time to peak effect, volume of distribution, duration of action, and elimination half-life in humans are unknown, but there are reports of late-onset coma (36 hours). In rats, only 1% of an oral dose is excreted in the urine and feces within 5 hours, and only 12% by 48 hours.
Toxic dose. Inhalation or ingestion of as little as 1 mg of fluoroacetate is sufficient to cause serious toxicity. Death is likely after ingestion of more than 2–10 mg/kg.
Clinical presentation. After a delay of minutes to several hours (in one report, coma was delayed 36 hours), manifestations of diffuse cellular poisoning become apparent; nausea, vomiting, diarrhea, metabolic acidosis (lactic acidosis), shock, renal failure, agitation, confusion, seizures, coma, respiratory arrest, pulmonary edema, and ventricular dysrhythmias may occur. One case series reported a high incidence of hypocalcemia and hypokalemia. Hypotension, acidemia, and elevated serum creatinine are the most sensitive predictors of mortality. Death is usually the result of respiratory failure or ventricular dysrhythmia.
Diagnosis is based on a history of ingestion and clinical findings, which may be delayed for several hours. Poisoning with fluoroacetate may mimic poisoning with other cellular toxins, such as hydrogen cyanide and hydrogen sulfide, although with these poisons the onset of symptoms is usually more rapid.
Specific levels. There is no assay available.
Other useful laboratory studies include electrolytes, glucose, BUN, creatinine, calcium, arterial blood gases, ECG, and chest radiography. Perform continuous ECG monitoring.
Emergency and supportive measures
Maintain an open airway and assist ventilation if necessary (See Airway and Breathing). Administer supplemental oxygen.
Replace fluid losses from gastroenteritis with IV saline or other crystalloids.
Treat shock (See Hypotension), seizures (See Seizures), and coma (See Coma and stupor) if they occur. Because of the reported potential delay in the onset of serious symptoms, it is prudent to monitor the patient for at least 36–48 hours.
Specific drugs and antidotes. Although several antidotes have been investigated, none have been proven ...