Effectiveness of add-on therapy with domperidone vs alginic acid in proton pump inhibitor partial response gastro-oesophageal reflux disease in systemic sclerosis: randomized placebo-controlled trial

Objectives. Twice-daily dosing of proton pump inhibitor (PPI), the standard therapy for gastro-oesophageal reflux disease (GERD), is an effective therapy for GERD in SSc. The aim of this study was to compare the efficacy of omeprazole in combination with domperidone vs in combination with algycon in reducing the severity and frequency of reflux symptoms of PPI partial response (PPI-PR) GERD in SSc. Methods. Adult SSc patients having PPI-PR GERD were randomly assigned to receive domperidone plus algycon placebo or algycon plus domperidone placebo in a 1: 1 ratio plus omeprazole for 4 weeks. The assessment included severity of symptom grading by visual analogue scale, frequency of symptoms by frequency scale for symptoms of GERD and quality of life (QoL) by EuroQol five-dimensions questionnaire scoring. Results. One hundred and forty-eight SSc-GERD patients were enrolled, of whom 88 had PPI-PR. Eighty cases were randomized for either domperidone (n = 38) or algycon (n = 37) therapy. The majority in both groups had the diffuse SSc subset. At the end of the study, no significant difference in symptom grading was found between groups. After treatment and compared with baseline, the severity of symptoms, frequency scale for symptoms of GERD and QoL significantly improved in both groups. Five (13.2%) and 8 (21.6%) respective cases in the domperidone and algycon groups did not respond. Conclusion. The prevalence of PPI-PR GERD is common. Domperidone and algycon are equally effective treatments in combination with omeprazole. However, similar to 17% of patients were non-responsive, so the effectiveness of domperidone, algycon and PPI combination therapy should be further investigated.