Paraquat Toxicity and Lipid Peroxidation

Paraquat (1,1′-dimethyl-4,4′-dipyridilium dichloride) is a commonly used, effective herbicide. When accidentally or intentionally ingested, paraquat is a multisystem poison capable of causing toxicity to the lungs, kidney, liver, brain, heart, and muscle.¹,²The compound is also corrosive to the mouth and skin¹,²; furthermore, percutaneous absorption of paraquat can result in systemic toxicity.³Without appropriate treatment, the mortality after ingestion of concentrates of paraquat (29.1% cationic solution) has ranged from 87% to 100%.⁴Injection of as little as 1 mL subcutaneously has been fatal.⁵ Although paraquat damages many tissues, important clinical toxicity usually involves the lungs and kidneys.¹,²Renal failure is common after paraquat ingestion and has been a cause of fatalities. However, this renal failure is reversible and can be managed by conventional means. The major respiratory complications of paraquat poisoning are pulmonary edema and fibrosis.¹,²Pulmonary edema usually appears within the first few days after ingestion; pulmonary fibrosis ordinarily