Tallman lettering

Tallman lettering (or Tall Man lettering) is the practice of writing part of a drug's name in upper case letters to help distinguish sound-alike, look-alike drugs from one another in order to avoid medication errors. Several studies have shown that highlighting sections of drug names using tallman letters can help distinguish similar drug names, making them less prone to mix-ups. ISMP, FDA, The Joint Commission, and other safety-conscious organizations have promoted the use of tallman letters as one means of reducing confusion between similar drug names.

Below are two lists with recommendations for the use of tallman lettering. The first list is of FDA-approved established drug names with recommended tallman letters, which were first identified during the FDA Name Differentiation Project. The second list is of additional drug names with recommendations from ISMP regarding the use and placement of tallman letters.

FDA's list
The following is a Food and Drug Administration approved list of generic drug names with tallman letters. The medications have been grouped to emphasize which medications are commonly mistaken by having sound sound-alike, look-alike names.

ISMP's list
The following is an Institute for Safe Medication Practices recommended list of drug names with tallman letters. The medications have been grouped to emphasize which medications are commonly mistaken by having sound sound-alike, look-alike names.

Difficulties with tallman lettering
One of the difficulties with the use of tallman lettering includes inconsistent application in health settings and lack of standardization regarding which letters to present in uppercase.