Top Line: Radiation enteritis is one of the most common on-treatment toxicities managed by radiation oncologists.
The Study: Loperamide is a commonly-prescribed μ-opioid receptor agonist that decreases peristalsis and increases transit time. Another widely-available option throughout Europe, Asia and South America (though not approved yet in the US) is Racecadotril, an anti-hypersecretory enkephalinase-inhibitor that does not slow motility and has been shown in a head to head comparison for non-radiation related acute diarrhea to be equally effective with less side effects. This Indian double-blind non-inferiority trial randomized 162 women with grade 2-3 diarrhea during or within 3 months of definitive radiation for a pelvic malignancy to one of either of these two oral agents. While the confidence interval was too wide to meet their prespecified definition of non-inferiority, the primary endpoint of improvement in diarrhea to grade 0-1 with 48 hours was numerically nearly identical: 68/81 (84%) after Racecadotril versus 70/81 (86%) after Loperamide. A secondary endpoint of rebound constipation was less likely after Racecadotril (6%) than Loperamide (17%), as was bloating or anorexia (0% versus 9%).
TBL: The anti-hypersecretory agent Racecadotril appears equally (very) effective with less side effects when compared to Loperamide for radiation enteritis, though it is not yet approved in the US. | Abhijith, Int J Radiat Oncol Biol Phys 2023
The Study: Loperamide is a commonly-prescribed μ-opioid receptor agonist that decreases peristalsis and increases transit time. Another widely-available option throughout Europe, Asia and South America (though not approved yet in the US) is Racecadotril, an anti-hypersecretory enkephalinase-inhibitor that does not slow motility and has been shown in a head to head comparison for non-radiation related acute diarrhea to be equally effective with less side effects. This Indian double-blind non-inferiority trial randomized 162 women with grade 2-3 diarrhea during or within 3 months of definitive radiation for a pelvic malignancy to one of either of these two oral agents. While the confidence interval was too wide to meet their prespecified definition of non-inferiority, the primary endpoint of improvement in diarrhea to grade 0-1 with 48 hours was numerically nearly identical: 68/81 (84%) after Racecadotril versus 70/81 (86%) after Loperamide. A secondary endpoint of rebound constipation was less likely after Racecadotril (6%) than Loperamide (17%), as was bloating or anorexia (0% versus 9%).
TBL: The anti-hypersecretory agent Racecadotril appears equally (very) effective with less side effects when compared to Loperamide for radiation enteritis, though it is not yet approved in the US. | Abhijith, Int J Radiat Oncol Biol Phys 2023