Botulinum Toxin: The Name Game
Your government at work.
Yesterday the FDA announced generic (or nonproprietary) name changes for 2 approved versions of injectable botulinum toxin.* Botox (Allergan), formerly botulinum toxin type A, is now onabotulinumtoxinA; and Myobloc (Solstice Neurosciences), formerly botulinum toxin type B, is now rimabotulinumtoxinB. The generic name for the most recently approved version, Dysport (Tercica), remains abobotulinumtoxinA. The names were changed to emphasize the different potencies of the products—the unit dosages of which are not interchangeable.
In the United States, nonproprietary names for drugs are assigned by the US Adopted Names (USAN) Council, a long-time collaboration among the American Medical Association, the US Pharmacopeial Convention, the American Pharmacists Association, and the FDA. The USAN Council works closely with the International Nonproprietary Names Programme of the World Health Organization to provide standardized and consistent drug names for worldwide use.
According to WHO, nonproprietary names “have to be distinctive in sound and spelling, and should not be liable to confusion with other names in common use”—an explanation which clarifies the unwieldy length of some generic drug names and their near unprounounceability. Pharmacologically related drugs should also share a common stem, which explains why all generic names for therapeutic monoclonal antibodies (mAbs) end with the -mab suffix (eg, rituximab, belimumab). For botulinum toxin products, the names are evidently distinguished by a short prefix (ie, ona-, rima-, and abo-) and the tail designator of “A” or “B,” which denotes the toxin type.
Clearly pharmaceutical marketers take advantage of cumbersome generic names by assigning catchier and easier-to-pronounce trade names. For instance, who’s going to say, “Hand me the syringe of onabotulinumtoxinA”?
* The FDA also announced that the labels of botulinum toxin drugs would now carry a boxed warning, describing the potential spread of the toxin and the attendant, possibly life-threatening effects.