Use of stems in the selection of International Nonproprietary Names (INN) for pharmaceutical substances, 2024

Overview

• Part I “Introduction” describes the WHO INN Programme, INN selection procedure and criteria for name selection and provides general information on the INN stem system.
• Part II contains the list of all INN stems. It is composed of two indexes, one entitled “Alphabetical list of common stems” which presents the list of stems, and another entitled “Alphabetical list of common stems and their definitions” which includes a definition for each stem.
• Part III presents the stem classification system used by the INN Programme to categorize the principal activity of pharmaceutical substances. Each category included in the list is given an appropriate code consisting of a capital letter and three digits. When INN for substances belonging to a given category include a specific stem, appropriate information is included in the table.
• Part IV of the document entitled “Alphabetical list of stems together with corresponding INN” serves as a listing of all proposed INN (published in Lists 1 - 129) containing INN stems. The list is organized in alphabetical order (as set out in Part II) and includes all INN containing a stem. In addition, under each stem heading, information is given on INN in which the preferred stem has been used but not in accordance with its definition, as well as on INN which belong to the same group of pharmaceutical substances but in which no preferred stem has been used. To facilitate the use of Part IV, the lay-out of information is presented as a diagram on page 7 and is complemented by additional information given at the end of part I “Introduction”.
• Six annexes attached to the document are intended to be of assistance to users.
  • Annex 1 reproduces the Procedure for the selection of recommended International Nonproprietary Names for pharmaceutical substances as approved by the World Health Organization (WHO) Executive Board in its resolution EB15.R7 as amended by resolution EB115.R4.
  • Annex 2 reproduces General Principles for guidance in devising International Nonproprietary Names for pharmaceutical substances as approved by the WHO Executive Board in the above-mentioned resolution, as amended.
  • Annex 3 explains the nomenclature scheme for monoclonal antibodies. Annex 4 explains the nomenclature scheme for gene therapy substances.
  • Annex 5 gives reference to the volumes of the WHO Drug Information in which proposed lists of INN have been published.
  • Annex 6 “Why INN ?” gives general information on the current situation of the WHO INN Programme and its achievements.