Interaction between whole-bowel irrigation solution and activated charcoal: implications for the treatment of toxic ingestions.

STUDY OBJECTIVES: The purpose of this study was to address the issues of safety and efficacy of combining whole-bowel irrigation and activated charcoal administration for the treatment of toxic ingestions.

STUDY DESIGN: Two in-vitro studies were performed. In the first, serial ratios of polyethylene glycol (PEG) and activated charcoal (AC) powders were added to water and the solutions were analyzed for PEG concentration and osmolality. In the second, serial ratios of a pharmaceutical bowel irrigation solution and an AC preparation were combined with a constant amount of salicylic acid. Solution osmolalities, PEG, and salicylic acid concentrations were then quantified.

RESULTS: Adsorption of PEG powder by AC was demonstrated; however, changes in solution osmolality were negligible. Thus, concurrent administration of these therapies appears safe. However, combining bowel irrigation solution with AC resulted in decreased salicylic acid adsorption. This was especially so with smaller amounts of AC that would pertain more to the smaller doses of AC used for multiple-dose charcoal therapy.

CONCLUSION: If these in-vitro data are applicable to overdose patients, the administration of a routine initial charcoal dose to those who will be treated with whole-bowel irrigation would be appropriate. However, it is unlikely that the addition of multiple-dose charcoal therapy to whole-bowel irrigation would provide additional benefit for the patient.