Efficacy of whole bowel irrigation using solutions with or without adsorbent in the removal of paraquat in dogs.

1. The efficacy of whole bowel irrigation with a solution containing either polyethylene glycol (PEG) with electrolyte or an adsorbent (Kayexalate with a cathartic (sorbitol) was investigated in 18 dogs who had been given 250 mg kg-1 paraquat dichloride via a jejunal tube to eliminate the influence of gastric absorption. 2. Plasma paraquat concentrations 2 and 3 h after the initiation of bowel irrigation and at the end of the study (5 h later) were significantly lower in the bowel irrigation groups than in the control (no bowel irrigation) group. 3. The total body clearances of paraquat in the bowel irrigation groups were significantly greater than in the control group. 4. There were no significant differences between the two different irrigation solution groups in plasma paraquat concentration, the area under the plasma concentration time curve and the total body clearance. 5. In the PEG with electrolyte group, about 70% of the administered dose of paraquat was removed by means of bowel irrigation (n = 4). 6. The adjunction of the adsorbent had no beneficial effects. 7. Haemodynamic changes associated with whole bowel irrigation were unremarkable except that right atrial and pulmonary arterial pressures were elevated in the latter part of the study.