01.02 Drug Nomenclature

An important issue to learn about at the start of a Unit in pharmacology is drug nomenclature. When I tell people that I am a pharmacologist, people often respond by saying “I’m taking Tenormin for my hypertension – do you know anything about this drug?” Tenormin is a tradename, and pharmacologists do not use trade names. So, I usually reply that “Tenormin is a tradename, and I can’t tell you anything about it unless you give me the real name of the drug”. Tenormin is actually atenolol, a β-blocker commonly used in the treatment of hypertension, and I know a lot about atenolol.

Each drug actually has 3 names. The first is the chemical name, and is the name used by chemists to describe the chemical structure. The second name is the generic, and this is the one used by pharmacologists. The generic name is also known as the non-proprietary name to distinguish it from the proprietary or trademark name. The trade name is used by the pharmaceutical companies. To give an example: the chemical name for diazepam is 7-chloro-1,3-dihydro-1-methyl-5-phenyl-2H-,1,4-benzodiazepin-2-on, and from this name, a chemist could draw the structure. The generic name is diazepam, which is a commonly used sedative. The third name is the proprietary or tradename. Each company can have a different tradename (brand name) for the same drug, the best known proprietary or tradename for diazepam is Valium (from the pharmaceutical company Roche), but other proprietary names for diazepam include Valpam (Arrow), Antenex (Alphapharm) and Ducene (Sauter). Thus, there are at least 4 different trade names for the same drug. Pharmaceutical companies probably like the use of their tradename, as this gives them some free advertising. However, it is more correct (and less confusing) to use generic names. Generic names are used throughout this Unit and eBook.