| Class | Bulk-forming laxative |
|---|---|
| Chemistry |
Highly branched acidic arabinoxylan starch |
| Routes of administration |
Oral |
| Absorption |
Non-absorbable |
| Solubility |
pKa of the polymers is 6.0; highly water-soluble |
| Distribution |
Not absorbed; remains in the bowel |
| Metabolism |
May undergo metabolism by gut bacteria |
| Elimination |
Eliminated largely unchanged in the stool |
| Time course of action |
Duration of effect depends largely on the gut motility |
| Target receptor |
Does not bind any cell receptors |
| Mechanism of action |
Forms a cross-linked mucilage gel which traps water and increases the mass and volume of stool. Some volatile fatty acids may also be released in the process, which have a prokinetic effect |
| Clinical effects |
An increase in the frequency, volume, and water content of stools. Theoretically, could cause bowel obstruction in large doses |
| Literature reference |
McRorie et al, 2021 |
| CICM details of understanding | Not specifically listed in the CICM syllabus |
| Mentioned around Deranged Physiology | |
| Related SAQs |