Metrifonate (

INN Inns are generally establishments or buildings where travelers can seek lodging, and usually, food and drink. Inns are typically located in the country or along a highway; before the advent of motorized transportation they also provided accommo ...

) or trichlorfon ( USAN) is an irreversible

organophosphate In organic chemistry, organophosphates (also known as phosphate esters, or OPEs) are a class of organophosphorus compounds with the general structure , a central phosphate molecule with alkyl or aromatic substituents. They can be considered a ...

acetylcholinesterase inhibitor. It is a

prodrug A prodrug is a medication or compound that, after intake, is metabolized (i.e., converted within the body) into a pharmacologically active drug. Instead of administering a drug directly, a corresponding prodrug can be used to improve how the drug ...

which is activated non-enzymatically into the active agent

dichlorvos Dichlorvos (2,2-dichlorovinyl dimethyl phosphate, commonly abbreviated as an DDVP) is an organophosphate widely used as an insecticide to control household pests, in public health, and protecting stored products from insects. The compound has bee ...

. It is used as an insecticide. According to the US

Environmental Protection Agency A biophysical environment is a biotic and abiotic surrounding of an organism or population, and consequently includes the factors that have an influence in their survival, development, and evolution. A biophysical environment can vary in scale f ...

trichlorfon has been used on golf course turf, home lawns, non-food contact areas of food and meat processing plants, ornamental shrubs and plants, and ornamental and baitfish ponds. Used to control caterpillars, white grubs, mole crickets, cattle lice, sod webworms, leaf miners, stink bugs, flies, ants, cockroaches, earwigs, crickets, diving beetle, water scavenger beetle, water boatman backswimmer, water scorpions, giant water bugs and pillbugs. After reregistration, a number of its uses were voluntarily restricted, and currently, it is used in nonfood areas to control flies, roaches, and ants among other pets. Outdoors it is used on

ornamental plant Ornamental plants or garden plants are plants that are primarily grown for their beauty but also for qualities such as scent or how they shape physical space. Many flowering plants and garden varieties tend to be specially bred cultivars that i ...

s, golf courses, and lawn grass to treat lepidopteran larvae pests, it is also used to treat flies in animal husbandry in areas that are not accessible to animals, it also used to control

harvester ants Harvester ant, also known as harvesting ant, is a common name for any of the species or genera of ants that collect seeds (called seed predation), or mushrooms as in the case of ''Euprenolepis procera'', which are stored in the nest in commun ...

. It can be used to treat

schistosomiasis Schistosomiasis, also known as snail fever, bilharzia, and Katayama fever, is a disease caused by parasitic flatworms called schistosomes. The urinary tract or the intestines may be infected. Symptoms include abdominal pain, diarrhea, bloody s ...

caused by '' Schistosoma haematobium'', but is no longer commercially available. It has been proposed for use in treatment of

Alzheimer's disease Alzheimer's disease (AD) is a neurodegeneration, neurodegenerative disease that usually starts slowly and progressively worsens. It is the cause of 60–70% of cases of dementia. The most common early symptom is difficulty in short-term me ...

, but use for that purpose is not currently recommended.

Bans and restrictions

In the United States, trichlorfon/metrifonate may only be used on nonfood and nonfeed sites. Trichlorfon/metrifonate was banned in the EU in 2008 (Regulation (EC) 689/2008) and in Brazil in 2010. Trichlorfon/metrifonate was banned in Argentina in 2018, noting that trichlorvon converts to

by metabolism in plants, as well as by biodegradation of the soil. Trichlorfon/metrifonate was banned in New Zealand in 2011. Trichlorfon/metrifonate was banned in India from 2020.

References

Acetylcholinesterase inhibitors Insecticides Antiparasitic agents Organophosphate insecticides Phosphonate esters Trichloromethyl compounds Prodrugs {{antiinfective-drug-stub