Treatment is primarily supportive and symptomatic. This post-emergent herbicide and its analogue diquat bind tightly to soil and does not leech out into the ground water, lessening the environmental impact. Mechanistically, in plants paraquat inhibits photosynthesis. It will initially produce a pulmonary toxicity characterised by a frothy pulmonary exudate. As toxicity progresses, the lungs and kidneys become fibrotic.
Death is usually due to respiratory failure.
Once paraquat has entered the pulmonary cells, there is no effective treatment for toxicity. Additionally, it may cause hepatotoxicity, presumably by a similar mechanism. Causes CNS excitation, convulsions, GI distention, hepatotoxicity, and nephrotoxicity. It is not taken up by type II epithelial cells and is therefore devoid of pulmonary toxicity. Acute ingestion may be treated by the administration of Fuller's Earth as a slurry, which binds the paraquat and prevents its absorption.