Multicenter randomized controlled clinical trial comparing ebastine and mebeverine as treatment of irritable bowel syndrome

Trial rationale

1. To perform a randomized superiority trial comparing the clinical efficacy of ebastine and mebeverine
2. To evaluate the impact of treatment with ebastine compared to mebeverine on quality of life and quality-adjusted life years

Primary objective To provide further evidence of the superiority of histamine 1 receptor antagonism as novel treatment for patients with non-constipated IBS, as compared to mebeverine, one of the spasmolytics currently used as first line treatment of IBS.

Secondary objective(s) To provide evidence that the histamine 1 receptor antagonist ebastine is more effective in reducing abdominal pain compared to the commonly used antispasmodic mebeverine

Inclusion Criteria:

1. Voluntary written informed consent of the participant or their legally authorized representative has been obtained prior to any screening procedures
2. Patients fulfilling the Rome IV criteria for non-constipated IBS (IBS-C subtypes will be excluded)
3. No organic cause that can explain the presenting symptoms (exclusion of coeliac disease (blood), lactose intolerance (breath test), inflammatory bowel disease and giardiasis (stool)
4. Patients with lactose intolerance can be included if no improvement on lactose free diet during 6 weeks
5. Age 18-65

Exclusion Criteria:

1. History of coeliac disease, food allergy, giardiasis, inflammatory bowel disease, infectious gastroenteritis, motility disorder, serious liver kidney cardiac or pulmonary disease, known cardiac rhythm disorders, insuline-dependent diabetes, psychiatric diseases
2. Pregnancy, breast feeding
3. Medication: the use of antidepressants or antipsychotics, anti-allergic medication or drugs affecting gastrointestinal motility / visceral sensitivity (anti-cholinergics, antispasmodics, 5-HT3 antagonists, 5-HT4 agonists, loperamide, codeine, laxatives, analgesics: only paracetamol is allowed as analgetic, other analgesics are forbidden.), CYP3A4-inducing and inhibiting drugs. Potent inhibitors of CYP3A4 include clarithromycin, erythromycin, diltiazem, itraconazole, ketoconazole, ritonavir, verapamil, goldenseal and grapefruit. Inducers of CYP3A4 include phenobarbital, phenytoin, rifampicin, St. John's Wort and glucocorticoids.
4. Symptoms started following abdominal surgery
5. IBS constipation dominant (IBS-C)
6. Hypersensitivity to the active substance or to any of the excipients listed in section 6.1 of the SmPC of the respective medicinal products