Paraquat

Paraquat (PQ), also known as methyl viologen, is fast acting, broad spectrum and non-selective herbicide, non-residual activity with contact and desiccant action. PQ is photosystem I (electron transport) inhibitor. Is used to control common weeds and grasses in a wide range of agricultural and non-agricultural settings, but due to its highly poisonous nature was soon categorized as a “restricted-use” herbicide. PQ when ingested, even in small quantities, has one of the highest acute toxicities among herbicides and intentional or accidental ingestion of concentrated solutions can result in death. The lung is a target organ of this pesticide that mediates toxicity via a redox cycling reaction and oxidative cellular damage. The clinical course in PQ poisoning is often protracted and there is no known antidote for this toxin.