From the Guidelines
Organophosphate poisoning causes a severe toxic reaction characterized by excessive stimulation of the nervous system, and the body reacts by exhibiting muscarinic and nicotinic toxicity, which can be life-threatening if not treated promptly and effectively. When organophosphates enter the body, they inhibit the enzyme acetylcholinesterase, which normally breaks down the neurotransmitter acetylcholine. This inhibition leads to acetylcholine accumulation at nerve junctions, causing overstimulation of both muscarinic and nicotinic receptors. The resulting symptoms can be remembered by the mnemonic SLUDGE: Salivation, Lacrimation, Urination, Defecation, Gastrointestinal distress, and Emesis. Patients may also experience bronchospasm, bronchorrhea, miosis (pinpoint pupils), bradycardia, hypotension, and increased secretions. Nicotinic effects include muscle fasciculations, weakness, paralysis, tachycardia, and hypertension. Central nervous system effects include anxiety, restlessness, seizures, and potentially respiratory depression leading to death, as noted in the 2023 American Heart Association focused update on the management of patients with cardiac arrest or life-threatening toxicity due to poisoning 1.
The treatment of organophosphate poisoning involves several key components, including:
- Decontamination to prevent further absorption and protect healthcare providers from exposure, which is crucial in preventing continued absorption and protecting healthcare providers from exposure 1
- Atropine administration to counter muscarinic effects, with a recommended initial dose of 1-2 mg, doubled every 5 minutes until full atropinization is achieved, as outlined in the 2023 American Heart Association guidelines 1
- Pralidoxime administration to reactivate the enzyme if given early, with a recommended dose of 1-2 g IV, as noted in the guidelines 1
- Supportive care, including airway management, to address the potential for respiratory depression and other life-threatening complications, as recommended in the guidelines 1
The use of atropine and pralidoxime is supported by the highest level of evidence, with a Class I recommendation for their use in the treatment of organophosphate poisoning, as noted in the 2023 American Heart Association guidelines 1. Additionally, early endotracheal intubation is recommended for life-threatening organophosphate or carbamate poisoning, as noted in the guidelines 1. The use of benzodiazepines, such as diazepam or midazolam, is also recommended to treat seizures and agitation in the setting of organophosphate or carbamate poisoning, as noted in the guidelines 1. Overall, the treatment of organophosphate poisoning requires prompt and effective intervention to prevent morbidity and mortality, and to improve quality of life.
From the FDA Drug Label
The FDA drug label does not answer the question.
From the Research
Body Reaction to Organophosphate Poisoning
The body's reaction to organophosphate poisoning is a complex process that involves the inhibition of cholinesterase and pseudo-cholinesterase activities, leading to the accumulation of acetylcholine at synapses and overstimulation of neurotransmission 2. This can result in a range of symptoms, including:
- Meiosis
- Change in mental status
- Hypersalivation
- Fasciculations
Clinical Course and Treatment
The clinical course of organophosphate poisoning can be severe and may require intensive care management 2. Treatment typically consists of intravenous atropine and oximes, such as pralidoxime 2, 3. In some cases, a continuous infusion of pralidoxime may be used to manage prolonged nicotinic symptoms 4.
Complications and Mortality
Organophosphate poisoning can lead to a range of complications, including:
- Respiratory failure
- Aspiration pneumonia
- Urinary system infection
- Convulsion
- Septic shock The mortality rate for organophosphate poisoning is high, and early diagnosis and treatment are critical to preventing a fatal outcome 2, 5.
Epidemiology and Prevention
Acute organophosphate poisoning is a major health issue in developing countries, where suicidal and occupational exposure are common 5. Preventing environmental exposure and increasing awareness of pesticide toxicity can help reduce the incidence of organophosphate poisoning and protect human health 5.