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The Medical Dictionary for Regulatory Activities was created for the purpose maintaining up-to-date terminology in regards to regulation of pharmacology, vaccines and things associated to pharmaceuticals. Going back to the introduction, the Medical Dictionary for Regulatory Activities (MedDRA) is responsible for data interoperability among organizations, Giannangelo put it very simply saying MedDRA is responsible for “medical product regulation and related electronic data interchange.” (page 234). Another source taken again from the journal of Ahima gave the definition, MedDRA is a global standard medical terminology used to classify adverse event information associated with the use of biopharmaceuticals and other medical products (e.g., medical devices and vaccines).


MedDRA started as a tool based on the United Kingdom’s Healthcare system has turned into the grand regulatory dictionary used by the World Health Organization (WHO). This medical dictionary was turned into an international standard by the International Conference on Harmonization of Technical Requirements for Registration of Pharmaceuticals for Human Use. The International Conference of Harmonization (ICH) adopted MedDRA in 1994. Since that time the ICH has worked not only to improve the terminology contained within MedDRA, but also to translate the dictionary into ten other languages other than its original English. With MedDRA being made available to desktop users in 1999, since then there have been 25 major upgrades to the extensive medical dictionary. Every March and September there is are implemented changes that can be submitted any time before December or June respectively. A user is able to submit up to 100 change requests every month if they wish to. Users can submit proposed updates, deletions, and additions. One of the biggest changes made took place in September 2010, the addition of toxic chemical terms to MedDRA. The interesting fact about the addition of toxic chemical terms was that only a few were added. According to MedDRA’s official website they were selected by the Alerting System for Chemical Health Threats (ASHT II) project. The reason only a few terms were added to MedDRA after the project was due to the fact that the majority of terms needed were already a current part of MedDRA.


A specialized hierarchy system containing five levels. According to two sources, both the Australian Department of Health, and the official MedDRA website, the hierarchy of terminology contains symptoms, signs, diseases, syndromes and diagnoses, medical device malfunctions, medication errors, medical, social and familial history information, medical and surgical procedures, approved uses for medications and medical devices. One built upon the base of the other, the base structure being Low-Level Terms which contains over 70,000 terms. The low level terms are the lowest form and it takes several LLT to derive the PT which is just a single word for a medical situation. The hierarchy continues to the top until the highest level one system organ class is concluded, which represents an etiology that fits a system in the human body. The example given in Giannangelo of a low level term is arrhythmia, Dysrhythmias, which leads to the Preferred Term Level which contains over 20,000 terms. An example is Arrhythmia, the preferred term out of the two LLT is provided. Which can then be taken to the next level High-Level Term containing almost 2,000 terms, then High-Level Group Term containing 300 terms. The final hierarchy is System Organ Class which contains only twenty-six terms. What about updating, deleting or adding terms? Users have the ability to submit changes for review. The process is not easy though.


A map of the process of submitting a change request is linked under reference eight on the references page. The process seems very time consuming, as it should be. Great care should be taken to make a change in MEDDRA codes, for the benefit of health professionals. The process requires clear cut indications of what the proposed change is and depending on if the change is simple or complex there is a different process to follow. Therefore, the proposer of the change must should clearly be able to identify with research and supporting evidence the benefits that will be reaped from the change and the reason for the change. The proposal should clearly outline all areas of MEDDRA affected by the requested change. Also, the proposal might contain the possible detriment to MEDDRA if the requested changes are not made. To even propose a change would take months to put together and make a logical proposal. The process of review has deadlines, and therefore, requires diligence on the part of the individual preparing a proposal. Nevertheless, to propose a change, the proposal must be well constructed, time must be taken to make sure the reasoning is sound throughout the proposal and that the supporting evidence is solidly placed in the research. Without a doubt the individual responsible for proposing a change must be well organized and have a well-rounded knowledge of MEDDRA categories and the hierarchical levels contained in the language. The person submitting a change must have extensive knowledge to even begin to form a change to the MEDDRA. The proposal should be constructed in a way that clearly highlights the changes in language being discussed and what is actually being requested and why, therefore, the changes that are most commonly used should be in the forefront of the proposal and not an afterthought to the changes that are rarely used. However, commonality should not be the only dictation, the hierarchy of need should be taken into consideration. Whatever the change is the benefit of the current system in place should be dire if the change is complex. The change request should not be something just thrown together by someone who thinks it may be of help. The request should be thoroughly considered beforehand, because requests are considered in an arena similar to that of congress. Therefore, the proposal should be beyond reproach and be able to stand its ground without further explanation, everything must be discussed and carefully placed for the change request to carry any weight behind it.


The Management Board for MedDRA is comprised of ten organizations. Starting with WHO, the European Union, United Kingdom Medicines and Healthcare Products Regulatory Agency, European Federation of Pharmaceutical Industries and Associations, (Ministry of Health, Labour and Welfare, Japan), Japan Pharmaceutical Manufacturers Association, International Federation of Pharmaceutical Manufacturers and Associations, Pharmaceutical Research and Manufacturers of America, Health Products and Food Branch, and finally the FDA. Certainly an influential management board, their ability to steer MedDRA and maintain a current international clinical vocabulary.


1. “healthcare terminologies and classifications: essential keys to interoperability” AHIMA/AMIA task force on terminologies, 2007

2. Giannangelo, Kathy, MA, RHIA, CCS, CPHIMA. Healthcare Code Sets, Clinical Terminologies, and Classifications Systems. Third Edition, 2015: AHIMA Press.

3. American Health Information Management Association. "internet resources for accurate coding and reimbursement practices (Updated)." Journal of AHIMA (Updated March 2010).

4. [internet] Available from:

5. International Council for Harmonization of Technical Requirements for Pharmaceuticals for Human Use

6. Australian Government Department of Health Therapeutic Goods Administration

7. J.J. Cimino. “desiderata for controlled medical vocabularies in the twenty-first century.” Meth Inform Med 1998; 37:394-403

8. request process.jpg

Submitted by Skyler Sommers