Effective treatment for paraquat poisoning in rats and its relevance to treatment of paraquat poisoning in man.

After oral administration of a lethal dose of paraquat to rats the plasma concentration remained relatively constant over four to 30 hours and was related to the paraquat content of the small intestine over the first 16 hours. During the first 30 hours the concentration of paraquat in the lung rose progressively above that of the plasma to levels which are known to cause pulmonary damage. A treatment has been devised which prevents the absorption of paraquat into the plasma and prevents accumulation of paraquat in the lung. This treatment consists of a stomach was followed by four administrations of bentonite plus purgatives at two- to three-hour intervals. Even when treatment was delayed until 10 hours after administration of paraquat 80% survival was obtained. The relevance of this treatment to paraquat poisoning in man is discussed in the light of the finding that slices of human lung accumulate paraquat in the same way as those of rat lung.