Whole-bowel irrigation as adjunctive treatment for sustained-release theophylline overdose

Abstract

To determine a therapeutic benefit for whole-bowel irrigation (with polyethylene glycol-electrolyte lavage solution) as adjunctive treatment to multiple doses of activated charcoal following an overdose of sustained-release theophylline. Randomized crossover study. Three treatment arms were separated by one-week intervals. Animal care facility housing. Eight female mongrel dogs. Unanesthetized dogs were given approximately 75 mg/kg of sustained-release theophylline. In treatment arm 1, 1 g/kg activated charcoal was administered by nasogastric tube at two hours after ingestion followed by 0.5-g/kg doses at five and eight hours. During treatment arm 2, beginning two hours after theophylline ingestion, 25 mL/kg whole-bowel irrigation solution was administered every 45 minutes for four doses followed by activated charcoal. In treatment arm 3, the first dose of activated charcoal was given ten minutes before beginning the whole-bowel irrigation protocol. Serum theophylline levels were measured at zero, two, four, five, eight, 12, 16, and 24 hours after ingestion. Mean serum theophylline levels, area under the curve (P = .13), and terminal half-lives (P = .69) for each treatment group were not statistically different. This negative study had an 81% power to detect a 50% reduction in the area under the curve by whole-bowel irrigation treatment. In this model, whole-bowel irrigation did not add to the therapeutic benefits of activated charcoal.