Tall Man lettering is an error prevention strategy used to reduce the risk of look-alike and sound-alike medicine names errors. Tall Man lettering uses a combination of lower and upper case letters to highlight the differences between look-alike and sound-alike medicine names, like fluOXETine and fluVOXAMine, helping to make them more easily distinguishable.

The purpose of Tall Man lettering is to help health professionals select or supply the right medicine. Tall Man lettering serves as a warning about the risk of confusing a particular medicine name based on the orthography of the medicine name. The small amount of published literature available shows that, at the minimum, Tall Man lettering will or should alert clinicians’ to medicines that are at risk of name confusion and possible medication error without increasing the risk of errors[1-8].

The Commission supports the use of Tall Man lettering as one of several ways to reduce the risk of getting medicine names confused.  Other interventions like barcode verification and premarket assessment processes also contribute to risk reduction.

The New Zealand Tall Man lettering list is now available and is recommended for use by:

  • software vendors in medicine pick or drop-down lists in pharmacy and prescriber systems, to support prescribing and dispensing activities
  • software vendors in medicine pick or drop-down lists requiring a person to select individual medicines as part of the creation of a clinical record or some other clinical tasks
  • users who download New Zealand Universal List of Medicines (NZULM) data to generate their own medicine lists for a variety of in-house uses, including drop-down lists in ‘smart’ pumps, electronic medicine administration records and automated dispensing cabinet screens such as PYXIS medicine storage layout.

The New Zealand Tall Man lettering list has 99 medicine name pairs and 20 individual medicines.  The numbers of medicines on the list will be kept to a minimum to prevent over-use.  Amendments to the list will only occur annually if required. A review of the list is currently underway.

Related Publications & Resources



  1. Australian Commission on Safety and Quality in Healthcare. Evaluating the effect of the Australian List of Tall Man Names. Australian Commission on Safety and Quality in Health Care, Sydney, June 2011. http://www.safetyandquality.gov.au/wp-content/uploads/2014/01/Evaluating-the-Effect-of-the-Australian-List-of-Tall-Man-Names.pdf external link last accessed 19 January 2012
  2. Darker IT, Gerrett D, FIlik R, Purdy K, Gale A. The influence of 'Tall Man' lettering on errors of visual perception in the recognition of written drug names. Ergonomics 2011; 54(1):21-33.
  3. FIlik R, Purdy K, Gale A, Gerrett D. Drug name confusion: evaluating the effectiveness of capital ("Tall Man") letters using eye movement data. Social Science and Medicine 2004; 59: 2597-601.
  4. Gerrett D, Gale A, Darker IT, FIlik R, Purdy KJ. Final Report of the Use of Tall Man Lettering to Minimise Selection Errors of Medicine Names in Computer Prescribing and Dispensing Systems: NHS Connecting for Health 2009.
  5. FIlik R, Purdy K, Gale A, Gerrett D. Labelling of Medicines and Patient Safety: Evaluating Methods of Reducing Drug Name Confusion. Human Factors 2006; 48(1):39-47.
  6. FIlik R, Price J, Darker IT, Gerrett D, Purdy K, Gale A. The Influence of Tall Man Lettering on Drug Name Confusion - A Laboratory-Based Investigation in the UK Using Younger and Older Adults and Healthcare Practitioners. Drug Saf 2010; 33:677-87.
  7. David U and Cohen MR.  A tall man lettering project to enhance medication safety. Farmacia hospitalaria 2011: 35(5): 223 – 224
  8. Gabriele S, Hyland S, Gosbee LL, Singh MD, Ninan A, Evans R, Evans, Fernandes O. Visual Differentiation in Look-alike Medication Names. Report to the Canadian Patient Safety Institute. February 10, 2012

Last updated 27/02/2017