First, there is room to increase the Senokot dose to eight tablets daily at bedtime. If this is not effective, it is possible to introduce polyethylene glycol and decrease the daily Senokot dosage. Sennosides (such as Senokot) and osmotic laxatives (such as polyethylene glycol or Lactulose) have a different mechanism of action. If the response to sennosides is inadequate, consider decreasing the dose by 50 percent and adding polyethylene glycol or Lactulose.

In frail, older adults, an osmotic laxative may be preferred to a higher dose of sennosides, as the former causes less cramping.

Reference

Twycross R, Wilcock A, Dean M. Canadian Palliative Care Formulary, 1st Canadian ed. Nottingham, UK: Palliativedrugs.com; 2010.