Adverse Event
Any unfavourable medical occurrence during or after treatment with a drug, regardless of whether it is caused by the drug. Adverse events range from mild (nausea, headache) to serious (hospitalisation, death). For GLP-1 receptor agonists, gastrointestinal events are the most commonly reported.
Technical Context
AE reporting in clinical trials follows MedDRA (Medical Dictionary for Regulatory Activities) terminology — a standardised coding system with System Organ Classes (e.g. gastrointestinal disorders), preferred terms (e.g. nausea), and lower-level terms (more specific descriptions). AEs are graded by severity (mild, moderate, severe) and assessed for causality relationship (related, possibly related, unlikely related, not related). Key summary metrics: incidence (proportion experiencing at least one event), exposure-adjusted incidence rate (events per patient-year of exposure), and treatment-emergent AEs (new or worsened after first dose). For GLP-1 RAs, gastrointestinal AEs (nausea 15-44%, vomiting 5-25%, diarrhoea 8-20%, constipation 5-15%) are the most common and drive most discontinuations.