Metrifonate


Metrifonate or trichlorfon is an irreversible organophosphate acetylcholinesterase inhibitor. It is a prodrug which is activated non-enzymatically into the active agent dichlorvos.
It is used as an insecticide.
It can be used to treat schistosomiasis caused by Schistoma haematobium, but is no longer commercially available.
It has been proposed for use in treatment of Alzheimer's disease, 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. Bayer, the registrant, voluntarily cancelled the use on sod farms and residential lawns. Bayer also voluntarily canceled all food, feed and field crop registrations.
Trichlorfon/metrifonate was banned in the EU in 2008 and in Brazil in 2010.
Trichlorfon/metrifonate was banned in Argentina in 2018, noting that trichlorvon converts to dichlorvos 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.