HL7 Terminology (THO), published by HL7 International - Vocabulary Work Group. This guide is not an authorized publication; it is the continuous build for version 6.1.0 built by the FHIR (HL7® FHIR® Standard) CI Build. This version is based on the current content of https://github.com/HL7/UTG/ and changes regularly. See the Directory of published versions

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NamingSystem: Medical Dictionary for Regulatory Activities

Official URL: http://terminology.hl7.org/NamingSystem/mdr				Version: 3.0.0
Active as of 2023-06-15			Responsible: MedDRA Maintenance and Support Services Organization (MedDRA MSSO); Mr. Patrick Revelle; MSSO Director	Computable Name: MedDRA

MedDRA is a multilingual standardised international medical terminology which can be used for regulatory communication and evaluation of data pertaining to medicinal products for human use. MedDRA is designed for use in the registration, documentation and safety monitoring of medicinal products through all phases of the development cycle (i.e., from clinical trials to post-marketing surveillance).#13;

MedDRA is structured as a five level hierarchy. System Organ Classes (SOCs) are the broadest terms (e.g., Cardiac disorders, Investigations). The lowest level of the terminology is the Lowest Level Term (LLT) level.