fenthion

Action and Spectrum

Actions and spectrum: 

Fenthion is an organophosphorus compound that is widely used as an insecticide and acaricide. Its primary mode of action involves inhibiting acetylcholinesterase, an enzyme crucial for the normal functioning of the nervous system in insects and other pests.

By inhibiting acetylcholinesterase, fenthion causes an accumulation of acetylcholine at nerve endings, leading to overstimulation of the nervous system and paralysis and death in the target pests. 

The spectrum of fenthion’s activity is broad and includes various insect pests and mites. It is commonly used in agriculture to control pests on crops such as fruits, vegetables, and cereals. Additionally, fenthion has applications in the control of pests in public health settings and for veterinary purposes.

Drug Interaction

Adverse Reaction

Frequency not defined 

Muscle weakness 

dizziness 

anxiety 

seizures 

Headache 

confusion 

Nausea 

Diarrhea 

Vomiting 

dementia 

abdominal pain 

Bronchoconstriction 

Hypotension 

Bradycardia 

Peripheral neuropathy 

cognitive impairment 

Black Box Warning

Black Box Warning: 

There is no specific black box warning associated with fenthion.

Contraindication / Caution

Contraindication/Caution: 

Contraindication: 

• Pregnancy and Lactation: fenthion may pose risks to the developing fetus, and exposure during pregnancy is discouraged. Likewise, it is often advised to avoid its use during lactation due to the potential for transfer to breast milk. 
• Children and Infants: Extreme caution is warranted when using fenthion around children and infants. Young individuals may be more susceptible to the toxic effects of organophosphorus compounds. 
• Health Conditions: Individuals with certain health conditions, such as respiratory or neurological disorders, may be at an increased risk of adverse effects from exposure to fenthion. Caution should be exercised in such cases. 
• Water Contamination: fenthion is known to be highly toxic to aquatic organisms. Therefore, its use is often restricted near water bodies to prevent environmental contamination. 

Caution: 

• Toxicity to Humans: fenthion is a cholinesterase inhibitor and can be toxic to humans. Exposure may occur through inhalation, skin contact, or ingestion. Protective clothing, including gloves and respiratory protection, should be worn during handling and application. 
• Children and Infants: Extreme caution is necessary when using fenthion in areas frequented by children and infants. They may be more susceptible to the toxic effects of organophosphorus compounds. 
• Proper Application: Apply fenthion according to recommended rates and application methods. Avoid overuse, as excessive application may increase the risk of exposure and environmental contamination. 
• Residue Management: Be aware of residue management practices, especially in food crops. Follow established waiting periods before harvesting to ensure that residues are within acceptable limits. 

Comorbidities: 

• Respiratory Conditions: Individuals with asthma or COPD, may be more susceptible to respiratory effects if exposed to fenthion. 
• Neurological Effects: fenthion is a cholinesterase inhibitor, and excessive exposure can lead to neurotoxic effects. Neurological conditions may be at an increased risk of adverse effects. 
• Environmental Impact: fenthion is highly toxic to aquatic organisms, and its use can contribute to environmental contamination. This may have indirect effects on human health through the food chain.

Pregnancy / Lactation

Pregnancy consideration: pregnancy category: not assigned 

Lactation: excreted into human milk: unknown 

Pregnancy category: 

• Category A: well-controlled and Satisfactory studies show no risk to the fetus in the first or later trimester. 
• Category B: there was no evidence of risk to the fetus in animal studies, and there were not enough studies on pregnant women. 
• Category C: there was evidence of risk of adverse effects in animal reproduction studies, and no adequate evidence in human studies must take care of potential risks in pregnant women.   
• Category D: adequate data with sufficient evidence of human fetal risk from various platforms, but despite the potential risk, and used only in emergency cases for potential benefits. 
• Category X: Drugs listed in this category outweigh the risks over benefits. Hence these categories of drugs need to be avoided by pregnant women. 
• Category N: There is no data available for the drug under this category. 

Pharmacology

Pharmacology: 

fenthion is an organophosphorus compound employed as an insecticide and acaricide. Its pharmacology is characterized by its ability to inhibit acetylcholinesterase, an essential enzyme in the nervous system of insects and pests. By disrupting cholinergic neurotransmission, fenthion induces the accumulation of acetylcholine at nerve synapses, leading to prolonged nerve stimulation, paralysis, and eventual death of the target organisms.

While effective in pest control, the neurotoxic mechanism of action raises concerns about its potential impact on non-target organisms and necessitates careful application and adherence to safety guidelines. The pharmacokinetic details, including absorption, distribution, metabolism, and excretion of fenthion, may vary depending on the formulation and the specific context of use.

Pharmacodynamics: 

• Inhibition of Acetylcholinesterase (AChE): fenthion acts as an acetylcholinesterase inhibitor. Acetylcholinesterase is responsible for breaking down the acetylcholine in the nervous system. By inhibiting AChE, fenthion leads to the accumulation of acetylcholine in the synaptic clefts of nerve cells. 
• Prolonged Stimulation of Cholinergic Receptors: The accumulation of acetylcholine results in continuous stimulation of cholinergic receptors in the nervous system. Cholinergic receptors are found in the muscles, central nervous system, and peripheral nervous system. 
• Cholinergic Overstimulation: Continuous stimulation of cholinergic receptors leads to overstimulation of the nervous system, affecting both muscarinic and nicotinic receptors. This overstimulation can cause hyperactivity in the nervous system and result in paralysis of the targeted pests. 
• Toxicity to Non-Target Organisms: While effective against pests, the non-selective inhibition of acetylcholinesterase raises concerns about the potential toxicity of fenthion to non-target organisms, including humans and other animals. 

Pharmacokinetics: 

• Absorption: fenthion is typically absorbed through different routes, including oral, dermal, and respiratory routes. The extent of absorption may depend on factors such as the formulation of the product, application method, and environmental conditions. 
• Distribution: Once absorbed, fenthion may distribute throughout the body. Its distribution is influenced by factors such as lipophilicity. fenthion and its metabolites can be distributed to various tissues. 
• Metabolism: fenthion undergoes metabolic transformation, primarily in the liver. The metabolic pathways involve the formation of various metabolites. The cytochrome P450 plays a role in metabolism of fenthion. 
• Excretion: Metabolites of fenthion are excreted, with the primary route being through urine. Biliary excretion is also possible. The elimination half-life of fenthion and its metabolites can vary. 

Adminstartion

Administration: 

fenthion is an organophosphorus compound that has been historically used as an insecticide and acaricide in agriculture and for controlling pests in various settings. However, the use of fenthion has been restricted in many regions due to its toxicity to humans and other non-target organisms. 

Patient Information Leaflet

Patient information leaflet 

Generic Name: fenthion 

Pronounced: fen-thee-on 

Why do we use fenthion? 

fenthion is an organophosphorus compound commonly used as an insecticide and acaricide. fenthion is widely used in agriculture to control a broad spectrum of pests that can damage crops. It is effective against insects such as aphids, caterpillars, thrips, and mites that can negatively impact crop yields.

fenthion may be employed in public health efforts to control disease vectors. In the agricultural sector, fenthion is used to protect livestock and poultry from external parasites such as ticks and mites. This helps improve animal health and prevent the spread of diseases.