This reference work has been enlarged and revised to include 3000 newly developed drugs and now compiles over 12000 chemically unique drugs with more than 105000 synonyms. The first three volumes list organo-chemical drugs arranged by increasing molecular formulas and provides the following information for each: an own consecutive number, the molecular formula, the Chemical Abstracts Service index number (CAS number), the structural formula, references, the synonyms used to identify the drugs (names adopted by certain institutions, common trivial names, names adopted by manufacturers, experimental names, abbreviations, and non-proprietary names proposed by the WHO that are marked by asterisks), characterization and therapeutic use. Volume four contains indices to facilitate working with the list and includes a group index (for finding drugs related to each other chemically or pharmacologically), the CAS number index and the index of synonyms.