Diphenyl methane laxatives do not induce electrolyte imbalance

Aim: To analyse whether there are changes in sodium and potassium serum levels during chronic treatment with the diphenyl methanes bisacodyl and sodium picosulfate. Methods: A literature search was done using PubMed, and the reference lists of pertinent papers were screened for additional studies. Only studies of at least 4 weeks duration were considered for further analysis. Results: Four relevant studies were identified. In three randomised controlled trials with 5 to 10 mg daily of bisacodyl or sodium picosulfate, respectively, over four weeks no electrolyte losses were found. Hypokalemia was also not a problem in a group of patients with paraplegia using bisacodyl suppositories for 2 to 34 years. Conclusions: Electrolyte losses, particularly hypokalemia, are not a problem when bisacodyl or sodium picosulfate are used long-term.