GERARD LEE, secretary and scientific director, BP Commission, replies:

The World Health Organization Expert Group on International Non-Proprietary Names (INNs) is responsible for creating and publishing INNs for new pharmaceutical substances.

INNs are used internationally and must meet the requirements of the international community. For example, there is no translation of “th” in Spanish. To facilitate the translation and pronunciation of INNs and to accommodate the publication languages of WHO, the use of the letters “h” and “k” are avoided, “e” is used instead of “ae” and “oe”, “i” instead of “y” and “t” and “f” instead of “th” and “ph”.

The INN programme started in 1950 and at that time many substances had well-established names, which were adopted in the early part of the programme. At that time also there were a number of BANs in established use, which were retained in the UK. The differences that existed between BANs and INNs were of historical nature and were to address conflict established with trademarks. The decision to implement fully in the UK the European Community Directive 92/27/EEC which authorises the use of recommended INNs in labelling of medicines throughout the European Community has been the basis of harmonising BANs and rINNs where there were differences. A list of names affected is on the Medicines and Healthcare products Regulatory Agency website.

Many of the examples quoted by Dr Schmidt are names adopted in the early part of the INN programme and the differences in the stem reflect the international name in common established usage at the time.