MedDRA — Medical Dictionary for Regulatory Activities

Overview

MedDRA is the international medical terminology developed under the auspices of the International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use (ICH). It is the required standard for adverse event coding in clinical trial regulatory submissions to the EMA, FDA, and national agencies including the French ANSM (Agence Nationale de Sécurité du Médicament).

Structure

MedDRA uses a five-level hierarchy:

1. SOC (System Organ Class) — top level, e.g. Nervous system disorders
2. HLGT (High Level Group Term)
3. HLT (High Level Term)
4. PT (Preferred Term) — the primary coding level for adverse events
5. LLT (Lowest Level Term) — most granular, maps to verbatim terms

Connections

• Integrated into: OMOP CDM (MedDRA vocabulary in Athena)
• Used with: CDISC (SDTM adverse event data uses MedDRA coding)

Resources

• https://www.meddra.org
• https://www.meddra.org/how-to-use/support-documentation/english (guides)
• https://www.ema.europa.eu/en/human-regulatory/research-development/data-medicines-iso-idmp-standards/eudravigilance/meddra (EMA MedDRA page)