Medical Dictionary for Regulatory Activities (MedDRA)

The Medical Dictionary for Regulatory Activities (MedDRA) is an internationally used set of terms relating to medical conditions, medicines and medical devices.

It was created to assist regulators with sharing information. It is also used by industry, academics, health professionals and other organisations that communicate medical information.

MedDRA terms in the Database of Adverse Event Notifications - medicines

We use MedDRA terms for coding the reports it receives about adverse events.

Before a report is entered into the Database of Adverse Event Notifications - medicines, the relevant MedDRA terms are assigned to describe the adverse event and other medical terms as necessary. 

This results in a consistent terminology, which enables related adverse events in DAEN - medicines to be grouped together in the medicine summary.

MedDRA terms

MedDRA includes standardised terms for:

• symptoms, signs, diseases, syndromes and diagnoses
• medical device malfunctions
• medication errors
• medical, social and family history information
• sites (e.g. application, implant and injection sites)
• medical and surgical procedures
• approved uses for medications and medical devices
• types of investigations (e.g. liver function analyses, metabolism tests).

MedDRA system organ classes

The MedDRA system organ class is defined as the highest level of the MedDRA terminology, distinguished by anatomical or physiological system, aetiology (disease origin) or purpose. Most of these describe disorders of a specific part of the body. For example:

• Cardiac disorders describe heart problems
• Renal and urinary disorders describe kidney and bladder problems
• Some of the system organ classes are not related to a particular part of the body. For example:
  • investigations describes laboratory tests and other medical investigations that gave an unusual reading
  • neoplasms describes any type of growth, including cancer, no matter where it appears in the body.

The 27 MedDRA system organ classes

The 27 system organ classes are:

1. Blood and lymphatic system disorders
2. Cardiac disorders
3. Congenital, familial and genetic disorders
4. Ear and labyrinth disorders
5. Endocrine disorders
6. Eye disorders
7. Gastrointestinal disorders
8. General disorders and administration site conditions
9. Hepatobiliary disorders
10. Immune system disorders
11. Infections and infestations
12. Injury, poisoning and procedural complications
13. Investigations
14. Metabolism and nutrition disorders
15. Musculoskeletal and connective tissue disorders
16. Neoplasms benign, malignant and unspecified (incl cysts and polyps)
17. Nervous system disorders
18. Pregnancy, puerperium and perinatal conditions
19. Psychiatric disorders
20. Renal and urinary disorders
21. Reproductive system and breast disorders
22. Respiratory, thoracic and mediastinal disorders
23. Skin and subcutaneous tissue disorders
24. Social circumstances
25. Surgical and medical procedures
26. Vascular disorders
27. Product issues.

MedDRA reaction terms

The term used to describe an adverse event in the Database of Adverse Event Notifications - medicines is the MedDRA 'preferred term', which describes a single medical concept.

Each MedDRA system organ class has a number of MedDRA preferred terms associated with it. For example, the system organ class 'cardiac disorders' includes (among others) the following preferred terms:

• angina
• cardiac arrest
• myocardial infarction
• palpitations.

The MedDRA Maintenance and Support Services Organization

The MedDRA Maintenance and Support Services Organization (MSSO) maintains and distributes MedDRA information. The MSSO releases updated versions of MedDRA twice a year to subscribers.

MedDRA was developed by the International Conference on Harmonisation of Technical Requirements for Registration of Pharmaceuticals for Human Use (ICH) to assist regulatory authorities to easily and accurately share information on therapeutic goods, including about adverse events to medicines.

MedDRA terminology incorporates terminology from the:

• Medicines and Healthcare products Regulatory Agency (MHRA)
• 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).