FDA Name Differentiation Project
FDA List of Established Drug Names Recommended to Use Tall Man Lettering (TML)
Tall man lettering (TML) is a technique that uses uppercase lettering to help differentiate look-alike drug names. Starting on the left side of a drug name, TML highlights the differences between similar drug names by capitalizing dissimilar letters (e.g., vinBLAStine versus vinCRIStine and CISplatin versus CARBOplatin).1 TML can be used along with color or bolding to draw attention to the dissimilarities between look-alike drug names, and alert healthcare providers that the drug name can be confused with another drug name.
In 2001, FDA initiated the name differentiation project to continually evaluate postmarketing reports of name pair confusion, and determine if TML should be used to help differentiate similar established names. The FDA evaluation considers multiple factors, including the degree of similarity between the name pair, safety risks with confusion between the name pair, overlapping product characteristics, reports of wrong drug errors, and causes or contributing factors. If FDA’s evaluation determines TML is an appropriate approach to address reports of name confusion, FDA will request the manufacturer voluntarily revise their labels and labeling to use TML, and then update the FDA List of Established Drug Names Recommended to Use Tall Man Lettering. FDA may also consider labeling revisions, safety communications, and other approaches to address reports of product name confusion.
1Institute for Safe Medication Practices. Special edition: tall man lettering; ISMP updates its list of drug names with tall man letters. 2016 Jun 2 [cited 2019 Aug 23].
The following is a list of the established drug names recommended to use tall man lettering:
| Established Name | Recommended Name |
|---|---|
| Acetohexamide Acetazolamide |
acetoHEXAMIDE acetaZOLAMIDE |
| Bupropion Buspirone |
buPROPion busPIRone |
| Chlorpromazine Chlorpropamide |
chlorproMAZINE chlorproPAMIDE |
| Cisplatin Carboplatin |
CISplatin CARBOplatin |
| Clomiphene Clomipramine |
clomiPHENE clomiPRAMINE |
| Cyclosporine Cycloserine |
cycloSPORINE cycloSERINE |
| Daunorubicin Doxorubicin |
DAUNOrubicin DOXOrubicin |
| Dimenhydrinate Diphenhydramine |
dimenhyDRINATE diphenhydrAMINE |
| Dobutamine Dopamine |
DOBUTamine DOPamine |
| Glipizide Glyburide |
glipiZIDE glyBURIDE |
| Hydralazine Hydroxyzine |
hydrALAZINE hydrOXYzine |
| Hydromorphone | HYDROmorphone |
| Medroxyprogesterone Methylprednisolone Methyltestosterone |
medroxyPROGESTERone methylPREDNISolone methylTESTOSTERone |
| Methylprednisolone Methyltestosterone |
methylPREDNISolone methylTESTOSTERone |
| Migalastat Miglustat |
migALAstat migLUstat |
| Mitoxantrone | mitoXANTRONE |
| Nicardipine Nifedipine |
niCARdipine NIFEdipine |
| Prednisone Prednisolone |
predniSONE prednisoLONE |
| Risperidone Ropinirole |
risperiDONE rOPINIRole |
| Sulfadiazine Sulfisoxazole |
sulfADIAZINE sulfiSOXAZOLE |
| Tolazamide Tolbutamide |
TOLAZamide TOLBUTamide |
| Trazodone Tramadol |
traZODone traMADol |
| Vinblastine Vincristine |
vinBLAStine vinCRIStine |