About the Medical Dictionary for Regulatory Activities

The Medical Dictionary for Regulatory Activities (MedDRA) is an internationally recognized set of terms used to facilitate the regulation of medical products for humans, including biopharmaceuticals, medical devices and vaccines. Developed by the  International Conference on Harmonisation of Technical Requirements for Registration of Pharmaceuticals for Human Use (ICH), MedDRA terminology is used throughout the regulatory process to enter, retrieve, analyse and present data both before and after a medical product has been authorized for sale. In addition, MedDRA enables the electronic transmission of adverse event reporting, in both pre- and post-marketing phases.

MedDRA serves a vital public health need. It allows health authorities and the biopharmaceutical and medical device industries within and between countries to accurately and easily share information regarding pre- and post-market medical product registration, including safety monitoring of products.

MedDRA Terminology

Major regulatory authorities throughout the world as well as pharmaceutical, biological and medical device manufacturing companies use MedDRA terminology. Academic organizations, researchers, hospitals and health professionals also use MedDRA. Any organization interested in communicating medical information during medical product development and marketing may apply MedDRA terminology.

MedDRA includes standardized terms for symptoms, signs, diseases, syndromes and diagnoses. In addition, it contains terms for:

  • Device malfunctions;
  • Medication errors;
  • Medical, social and family history information;
  • Sites (e.g., application, implant and injection site reactions);
  • Surgical and medical procedures;
  • Therapeutic indications
  • Types of investigations (e.g., liver function analyses, metabolism tests).

MedDRA terminology is based on the medical terminology of the  United Kingdom's Medicines and Healthcare products Regulatory Agency (MHRA) and incorporates terminology from the following entities:

  • World Health Organization Adverse Reaction Terminology (WHO-ART)
  • International Classification of Diseases (ICD)
  • International Classification of Diseases and Clinical Modification (ICD-CM)
  • Coding Symbols for a Thesaurus of Adverse Reaction Terms (COSTART)
  • Japanese Adverse Reaction Terminology (J-ART)

Health Canada's Use of MedDRA

To communicate regulatory information effectively, Health Canada uses the internationally recognized MedDRA terminology for the following pre- and post-market activities involving health products:

  • To express medical concepts in certain modules of the Common Technical Document (CTD), a standard format for the preparation of new drug product submissions.  Also see the Common Technical Document - ICH Topic M4.
  • To describe adverse reactions in drug product monographs. See the Guidance for Industry.
  • To code adverse reaction reports submitted to the Canada Vigilance Program by industry, health professionals and consumers related to marketed health products covered by the Food and Drugs Act, Food and Drug Regulations, and Natural Health Products Regulations. In the Guidance Document for Industry - Reporting Adverse Reactions to Marketed Health Products, Health Canada recommends the use of MedDRA as a standard for the coding of adverse reaction reports.

Maintaining MedDRA

The  MedDRA Maintenance and Support Services Organization (MSSO) serves as the repository, maintainer and distributor of MedDRA information. Updates to MedDRA terminology are made in biannual version releases distributed in March and September, which MedDRA subscribers receive via email. MedDRA subscribers can request additions, deletions or propose other changes to the terminology through a structured change request process available through the MSSO.

Additional Information

For information about how to subscribe to MedDRA, training opportunities, MedDRA User Group Meetings, as well as information regarding the MedDRA Points to Consider documents, contact the  MedDRA Maintenance and Support Services Organization (MSSO).

For more information on Health Canada's use of MedDRA, contact the Canada Vigilance Program.

Report a problem or mistake on this page
Please select all that apply:

Privacy statement

Thank you for your help!

You will not receive a reply. For enquiries, contact us.

Date modified: