Recommendations

Look-Alike Drug Names with Recommended Tall Man Letters

ISMP's List of Look-Alike Drug Names with Recommended Tall Man Letters contains drug name pairs and trios with recommended, bolded tall man (uppercase) letters to help draw attention to the dissimilarities in look-alike drug names. The list includes mostly generic-generic drug name pairs, although a few brand-brand or brand-generic name pairs are included. The US Food and Drug Administration (FDA) list of drug names with recommended tall man letters was initiated in 2001 with the agency’s Name Differentiation Project.

Table 1 provides an alphabetized list of FDA-approved established drug names with recommended tall man letters.

Table 2 provides an alphabetized list of additional drug names with recommendations from ISMP regarding the use and placement of tall man letters. This is not an official list approved by FDA. It is intended for voluntary use by healthcare practitioners, drug information vendors, and medication technology vendors. Any product label changes by manufacturers require FDA approval.

 

Table 1. FDA-Approved List of Generic Drug Names with Tall Man Letters

Drug Name With Tall Man Letters Confused With
acetaZOLAMIDE acetoHEXAMIDE
acetoHEXAMIDE acetaZOLAMIDE
buPROPion busPIRone
busPIRone buPROPion
chlorproMAZINE chlorproPAMIDE
chlorproPAMIDE chlorproMAZINE
clomiPHENE clomiPRAMINE
clomiPRAMINE clomiPHENE
cycloSERINE cycloSPORINE
cycloSPORINE cycloSERINE
DAUNOrubicin DOXOrubicin
dimenhyDRINATE diphenhydrAMINE
diphenhydrAMINE dimenhyDRINATE
DOBUTamine DOPamine
DOPamine DOBUTamine
DOXOrubicin DAUNOrubicin
glipiZIDE glyBURIDE
glyBURIDE glipiZIDE
hydrALAZINE hydrOXYzine – HYDROmorphone
HYDROmorphone hydrOXYzine — hydrALAZINE
hydrOXYzine hydrALAZINEHYDROmorphone
medroxyPROGESTERone methylPREDNISolone - methylTESTOSTERone
methylPREDNISolone medroxyPROGESTERone - methylTESTOSTERone
methylTESTOSTERone medroxyPROGESTERone - methylPREDNISolone
mitoXANTRONE Not specified
niCARdipine NIFEdipine
NIFEdipine niCARdipine
prednisoLONE predniSONE
predniSONE prednisoLONE
risperiDONE rOPINIRole
rOPINIRole risperiDONE
sulfADIAZINE sulfiSOXAZOLE
sulfiSOXAZOLE sulfADIAZINE
TOLAZamide TOLBUTamide
TOLBUTamide TOLAZamide
vinBLAStine vinCRIStine
vinCRIStine vinBLAStine

 

Table 2. ISMP List of Additional Drug Names with Tall Man Letters***

Drug Name With Tall Man Letters Confused With
ALPRAZolam LORazepam — clonazePAM
aMILoride amLODIPine
amLODIPine aMILoride
ARIPiprazole RABEprazole
AVINza INVanz*
azaCITIDine azaTHIOprine
azaTHIOprine azaCITIDine
carBAMazepine OXcarbazepine
CARBOplatin CISplatin
ceFAZolin cefoTEtan — cefOXitin — cefTAZidime — cefTRIAXone
cefoTEtan ceFAZolin — cefOXitin — cefTAZidime — cefTRIAXone
cefOXitin ceFAZolin — cefoTEtan — cefTAZidime — cefTRIAXone
cefTAZidime ceFAZolin — cefoTEtan — cefOXitin — cefTRIAXone
cefTRIAXone ceFAZolin - cefoTEtan – cefOXitin – cefTAZidime
CeleBREX CeleXA*
CeleXA CeleBREX*
chlordiazePOXIDE chlorproMAZINE**
chlorproMAZINE** chlordiazePOXIDE
CISplatin CARBOplatin
cloBAZam clonazePAM
clonazePAM cloNIDine — cloZAPine — cloBAZam — LORazepam
cloNIDine clonazePAM – cloZAPine — KlonoPIN*
cloZAPine clonazePAM — cloNIDine
DACTINomycin DAPTOmycin
DAPTOmycin DACTINomycin
DEPO-Medrol* SOLU-Medrol*
diazePAM dilTIAZem
dilTIAZem diazePAM
DOCEtaxel PACLitaxel
DOXOrubicin** IDArubicin
DULoxetine FLUoxetine — PARoxetine
ePHEDrine EPINEPHrine
EPINEPHrine ePHEDrine
epiRUBicin eriBULin
eriBULin epiRUBicin
fentaNYL SUFentanil
flavoxATE fluvoxaMINE
FLUoxetine DULoxetine — PARoxetine
fluPHENAZine fluvoxaMINE
fluvoxaMINE fluPHENAZine - flavoxATE
guaiFENesin guanFACINE
guanFACINE guaiFENesin
HumaLOG* HumuLIN*
HumuLIN* HumaLOG*
hydrALAZINE** hydroCHLOROthiazide – hydrOXYzine**
hydroCHLOROthiazide hydrOXYzine** — hydrALAZINE**
HYDROcodone oxyCODONE
HYDROmorphone** morphine — oxyMORphone
HYDROXYprogesterone medroxyPROGESTERone**
hydrOXYzine** hydrALAZINE** — hydroCHLOROthiazide
IDArubicin DOXOrubicin** – idaruCIZUmab
idaruCIZUmab IDArubicin
inFLIXimab riTUXimab
INVanz* AVINza*
ISOtretinoin tretinoin
KlonoPIN* cloNIDine
LaMICtal* LamISIL*
LamISIL* LaMICtal*
lamiVUDine lamoTRIgine
lamoTRIgine lamiVUDine
levETIRAcetam levOCARNitine — levoFLOXacin
levOCARNitine levETIRAcetam
levoFLOXacin levETIRAcetam
LEVOleucovorin leucovorin
LORazepam ALPRAZolam — clonazePAM
medroxyPROGESTERone** HYDROXYprogesterone
metFORMIN metroNIDAZOLE
methazolAMIDE methIMAzole — metOLazone
methIMAzole metOLazone – methazolAMIDE
metOLazone methIMAzole — methazolAMIDE
metroNIDAZOLE metFORMIN
metyraPONE metyroSINE
metyroSINE metyraPONE
miFEPRIStone miSOPROStol
miSOPROStol miFEPRIStone
mitoMYcin mitoXANTRONE**
mitoXANTRONE** mitoMYcin
NexAVAR* NexIUM*
NexIUM* NexAVAR*
niCARdipine** niMODipine – NIFEdipine**
NIFEdipine** niMODipine — niCARdipine**
niMODipine NIFEdipine** – niCARdipine**
NovoLIN* NovoLOG*
NovoLOG* NovoLIN*
OLANZapine QUEtiapine
OXcarbazepine carBAMazepine
oxyCODONE HYDROcodone — OxyCONTIN*– oxyMORphone
OxyCONTIN* oxyCODONE – oxyMORphone
oxyMORphone HYDROmorphone** — oxyCODONE – OxyCONTIN*
PACLitaxel DOCEtaxel
PARoxetine FLUoxetine — DULoxetine
PAZOPanib PONATinib
PEMEtrexed PRALAtrexate
penicillAMINE penicillin
PENTobarbital PHENobarbital
PHENobarbital PENTobarbital
PONATinib PAZOPanib
PRALAtrexate PEMEtrexed
PriLOSEC* PROzac*
PROzac* PriLOSEC*
QUEtiapine OLANZapine
quiNIDine quiNINE
quiNINE quiNIDine
RABEprazole ARIPiprazole
raNITIdine riMANTAdine
rifAMPin rifAXIMin
rifAXIMin rifAMPin
riMANTAdine raNITIdine
RisperDAL* rOPINIRole**
risperiDONE** rOPINIRole**
riTUXimab inFLIXimab
romiDEPsin romiPLOStim
romiPLOStim romiDEPsin
rOPINIRole** RisperDAL*— risperiDONE**
SandIMMUNE* SandoSTATIN*
SandoSTATIN* SandIMMUNE*
sAXagliptin SITagliptin
SEROquel* SINEquan*
SINEquan* SEROquel*
SITagliptin sAXagliptin — SUMAtriptan
Solu-CORTEF* SOLU-Medrol*
SOLU-Medrol* Solu-CORTEF* — DEPO-Medrol*
SORAfenib SUNItinib
SUFentanil fentaNYL
sulfADIAZINE** sulfaSALAzine
sulfaSALAzine sulfADIAZINE**
SUMAtriptan SITagliptin — ZOLMitriptan
SUNItinib SORAfenib
TEGretol* TRENtal*
tiaGABine tiZANidine
tiZANidine tiaGABine
traMADol traZODone
traZODone traMADol
TRENtal* TEGretol*
valACYclovir valGANciclovir
valGANciclovir valACYclovir
ZOLMitriptan SUMAtriptan
ZyPREXA* ZyrTEC*
ZyrTEC* ZyPREXA*

*Brand names always start with an uppercase letter. Some brand names incorporate tall man letters in initial characters and may not be readily recognized as brand names. An asterisk follows all brand names on the ISMP list.

** These drug names are also on the FDA list.

*** The ISMP list is not an official list approved by FDA. It is intended for voluntary use by healthcare practitioners and drug information and technology vendors. Any manufacturers’ product label changes require FDA approval.

To promote standardization regarding which letters to present in uppercase, ISMP follows a tested methodology whenever possible called the CD3 rule.15 The methodology suggests working from the left of the drug name first by capitalizing all the characters to the right once 2 or more dissimilar letters are encountered, and then, working from the right, returning 2 or more letters common to both words to lowercase letters. When the rule cannot be applied because there are no common letters on the right side of the name, the methodology suggests capitalizing the central part of the word only. When application of this rule fails to lead to the best tall man lettering option (e.g., makes names appear too similar, makes names hard to read based on pronunciation), an alternative option is considered. ISMP suggests that the bolded, tall man lettering scheme provided by FDA and ISMP for the drug name pairs listed in Tables 1 and 2 be followed to promote consistency.

More Recommendations

This list includes look-alike and sound-alike name pairs. Use this list to determine which medications require special safeguards to reduce the risk of errors and minimize harm.
This list includes medications that should not be crushed because of their special pharmaceutical formulations or characteristics, such as sustained release.