WHO naming stem · suffix · former · 10 listed names
-toin
antiepileptics, hydantoin derivatives
Where it sits in a name
WHO writes the stem as -toin. So the letters toin sit at the end of the name (…toin).
WHO marks this stem (d): formerly used and no longer formally acknowledged. The names below keep it.
All 10 names WHO lists under -toin
These are the INN in group (a) of Part IV of the stem book: names in which WHO says the stem is used as defined. The stem is marked where WHO places it. A-Z as WHO lists them.
- albutoin
- clodantoin
- ethotoin
- fosphenytoin
- imepitoin
- mephenytoin
- metetoin
- nitrofurantoin
- phenytoin
- ropitoin
Decode another name
Decoded
albutoin
Listed INNCarries the WHO stem -toin
- -toinend of the nameWHO lists it hereformer stemWHO definition: antiepileptics, hydantoin derivatives
“albutoin” is an INN that WHO lists under -toin in the 2024 stem book. A stem marked “former” is one WHO no longer formally acknowledges.
The same decoder as the front page: it reads the letters of a name against all 482 WHO stems, in your browser.
Source and licence
The definition of -toin (Part II B) and the 10 names (Part IV, group (a)) are from Use of stems in the selection of International Nonproprietary Names (INN) for pharmaceutical substances, 2024 (World Health Organization, Stem book 2024 (ISBN 978-92-4-009938-8); covers proposed INN Lists 1-129). Checked .
Adapted from: Use of stems in the selection of International Nonproprietary Names (INN) for pharmaceutical substances, 2024. Geneva: World Health Organization; 2024. Licence: CC BY-NC-SA 3.0 IGO. This adaptation was not created by WHO; WHO is not responsible for its content or accuracy and does not endorse this site. The data file stems.json is shared under the same licence.