New stems

Whenever possible, the USAN Council will assign substances to existing stems or nomenclature schemes that describe the substance, or the substance's action or use.  A new stem will be created only in the unusual circumstances where existing stems and nomenclature schemes do not accurately represent a compound, or the compound's action, structure or use, and also when substantial clinical and preclinical data support the creation of a new stem. 

The following listing of new stems was approved by the USAN Council at the January 25, 2008 USAN Council meeting:

New stems