Ramosetron relieves low anterior resection syndrome

Prof. Kyu Joo Park (Seoul National University Hospital, Korea) reported a randomised controlled trial to assess the effectiveness of ramosetron, a serotonin (5-hydroxytryptamine [5-HT]₃) receptor antagonist, for the treatment of anterior resection syndrome. Ramosetron significantly improved both the Low Anterior Resection Syndrome (LARS) score, as well as quality of life [1].

5-HT₃ receptor antagonists are effective for the treatment of irritable bowel syndrome, in which exaggerated intestinal/colonic hypermotility is observed. Recent studies have suggested that the motility disorder, especially spastic hypermotility, seen in the neorectum following sphincter-preserving operations for rectal cancer may be the basis of the post-operative defecatory malfunction seen in in 60-90% of patients, and for whom there are no effective treatments.

The investigators wished to investigate whether 5-HT3 receptor antagonist ramosetron could be effective in male patients suffering from severe low anterior resection syndrome after rectal cancer surgery. Enrolled patients were randomly allocated to an arm taking ramosetron 5 mg daily (n=48) or to conservative treatment (n=50) for 1 month. The LARS questionnaire determined the LARS score at the study start and after 1 month after treatment [2], which was the primary endpoint of the study. The secondary endpoint was the difference of patients' quality of life as assessed by the of EORTC QLQ-C30 questionnaire. Patient characteristics did not differ between arms regarding tumour distance from the anal verge, stage of the tumour, stool frequency, or mean LARS score at start of study.

After 1 month, the LARS score significantly decreased from 36.0 ± 5.9 to 29.6 ± 9.3 in the ramosetron group (P<0.001) and it was significantly lower in the ramosetron group than in the control group (29.6 ± 9.3 vs 34.6 ± 7.6; P=0.004). The mean change in LARS score (1 month - baseline) was also significantly different (-6.48 in ramosetron vs 0.16 in the control group; P<0.001). The proportion of severe LARS (LARS score ≥30) after 1 month was 58.3% (n=28/48) in the ramosetron group vs 82.0% (n=41/50) in the control group (P=0.011). The stool frequency after 1 month was 7.1/day vs 10.5/day in the ramosetron and control group, respectively (P=0.004). Patients with <4 stools/day were 13 (27.1%) in the ramosetron group vs 1 (2.0%) in the control group (P<0.001). Furthermore, the quality of life after 1 month was significantly better in ramosetron group in terms of general health status, physical functioning, emotional functioning, and cognitive functioning.

1. Park KJ et al. UEG Week 2019, Abstract OP241.
2. Emmertsen KJ, Laurberg S. Ann Surg 2012;255:922-8.

Posted on 23 October, 201928 March, 2024