Open-label pilot study of ethosuximide as adjunctive therapy for relieving abdominal pain related to Irritable Bowel Syndrome.

What Is Known And Objectives: There is clear evidence for an association between irritable bowel syndrome (IBS) and visceral hypersensitivity. This clinical study aimed to assess the adjunct role of ethosuximide, an antiepileptic drug with T-type calcium channel blocking activity, in the relieving of IBS-related abdominal pain.

Methods: This is a prospective, 3-month, randomized and controlled study of parallel groups. Fifty outpatients who met the inclusion criteria participated in the trial. Patients were allocated randomly: 25 received mebeverine 135 mg three times daily (t.i.d), whereas the other 25 received mebeverine 135 mg t.i.d and ethosuximide 500 mg t.i.d. At baseline and 12 weeks after starting the drug, patients were evaluated by a gastroenterologist. Serum tumour necrosis factor-alpha (TNF-alpha), interleukin-6 (IL-6), interleukin-8 (IL-8), faecal myeloperoxidase and faecal neutrophile gelatinase-associated lipocalin (NGAL) levels were tested before and after treatment. The Numeric Pain Rating Scale (NRS) was assessed before and after three months of therapy.

Results And Discussion: After 12 weeks, the ethosuximide group showed a statistically and significantly greater reduction in the serum levels of TNF-α, IL-6, IL-8, faecal myeloperoxidase and faecal NGAL in comparison with the control group after the treatment. Moreover, the ethosuximide group showed a statistically significant decrease in NRS compared with the mebeverine group.

What Is New And Conclusion: Ethosuximide could be a promising adjunct to antispasmodics in the treatment of IBS patients. Trial registration identifier: NCT04217733.