Gastrointestinal Adverse Effects

A symptom score of 4 or higher for any gastrointestinal outcome is considered a severe adverse effect. The trial assesses abdominal pain, reflux, nausea, diarrhoea, and loss of appetite using a questionnaire. Gastrointestinal adverse effects are a primary focus because they are common with metformin and may cause discontinuation and lower quality of life. Metformin users had a 7.7-fold higher risk of gastrointestinal adverse effects than placebo users in prior evidence. Because metformin adverse effects are dose-dependent, the higher-dose group is expected to experience more adverse effects.