Clinical Efficacy of Montelukast on Functional Dyspepsia Patients with Duodenal Eosinophilia: A Double-Blind Placebo Controlled Trial

Background: Functional dyspepsia (FD) is the second most common functional gastrointestinal disorder, associated with significant morbidity and impaired quality of life. Duodenal eosinophilia has emerged as a key pathophysiological mechanism underlying FD. Montelukast, a cysteinyl leukotriene receptor antagonist, has shown efficacy in pediatric FD with duodenal eosinophilia, but evidence in adults remains absent. This study aimed to determine the clinical efficacy of montelukast in adult patients with functional dyspepsia and duodenal eosinophilia. Methods: A randomized, double-blind, placebo-controlled parallel group trial was conducted at the Department of Gastroenterology, Bangabandhu Sheikh Mujib Medical University (BSMMU), Dhaka, from December 2021 to July 2023. Seventy-six adults with Rome IV-diagnosed FD and duodenal eosinophil count greater than 22/5HPF were randomized into two groups of 38 each. Group A received montelukast 10 mg daily and Group B received an identical placebo for four weeks. Symptom severity was assessed using a 5-point Likert scale at baseline and on day 29. Results: The majority of participants (46.1%) were aged 20 to 30 years and most were female. At baseline, both groups were comparable in age, sex, eosinophil count and Likert scores. Following treatment, a positive clinical response was observed in 94.7% of the montelukast group compared with 39.5% in the placebo group (p<0.001). Significant improvements were noted across all four symptom components including postprandial fullness, early satiation, epigastric pain and epigastric burning. Conclusion: Montelukast produced significant symptomatic improvement in adult FD patients with duodenal eosinophilia. It may be prescribed as an adjunct to conventional therapy in this patient population.