PTCB Guide to Tall-Man Lettering.

What is Tall Man Lettering?

Research shows that up to 77 percent of medication errors are preventable. And according to the AMCP, at least 1.5 million people in the US each year are harmed by medication errors.

Given the prevalence of medication errors, strategies have been developed in an attempt to reduce these numbers. One of those medication safety strategies is tall-man lettering.

Tall man lettering is a strategy used to reduce errors caused by sound-alike and look-alike drug names – often known by the acronym, SALAD drugs (or LASA drugs). It involves writing specific parts of a drug name in uppercase letters to highlight the differences between similar names. For example, predniSONE vs. prednisoLONE or hydrOXYzine vs. hydrALAZINE. By emphasizing the distinct sections of each name, tall man lettering helps healthcare professionals quickly distinguish between medications, especially in fast-paced environments like pharmacies.

This system is recommended by organizations such as the Institute for Safe Medication Practices (ISMP) and is commonly used in prescribing systems, labeling, and pharmacy workflows. It is particularly important in preventing dispensing and administration errors that could lead to serious patient harm.

Tall Man Lettering as a Topic of the PTCB Exam.

Tall man lettering is tested under the Patient Safety and Quality Assurance knowledge domain (23.75% of the exam).

As stated by the official PTCB outline:

• Topic: high alert / risk medications and look-alike/sound-alike (LASA) medications
• About: covers identification and management of high-alert drugs (e.g. insulin, anticoagulants, opioids, chemotherapy) and LASA medications (e.g. hydrOXYzine vs. hydrALAZINE). Emphasizes strategies like separate storage, color coding, and tall man lettering to minimize confusion and prevent errors.

Note that pharmacy technicians are not required to memorize all look-alike/sound-alike (LASA) drugs as listed by the ISMP.

Instead, technicians are required to learn:

• Definition – what tall-man lettering means.
• Purpose – functions and clinical value of tall-man lettering.
• Identification – to be able to identify the strategy in an exam question (see below for examples). Though we would strongly recommend trying to learn some key examples and common pairs.
• Where it’s used – prescription labels, pharmacy systems, medication storage, and electronic health records.
• Who recommends it – the ISMP
• Wider context – tall man lettering is one of many strategies taken together to mitigate the risk of medication errors alongside verifying drug name, strength, dosage form, patient details, NDC code, and bar codes.

Tall Man Lettering in Practice.

As we learned, tall-man lettering refers to the practice of using capital letters on part of a drug or medicine name to help differentiate it from a similarly sounding/looking drug or medicine.  

There are two kinds of tall-man lettering – lettering recommended by the FDA and lettering recommended by the ISMP.

For example:

• prednisoLONE and predniSONE
• ALPRAZolam and LORazepam
• HYDROcodone and oxyCODONE
• PARoxetine and FLUoxetine
• traMADol and traZODone

For example, when selecting drugs from a dispensing system, a technician may see hydrOXYzine and hydrALAZINE listed closely together. The use of tall man lettering helps draw attention to the differences, prompting a more careful check before selection. Similarly, when preparing labels, systems may automatically display predniSONE and prednisoLONE with highlighted lettering to reduce the risk of choosing the wrong product.

In storage areas, tall man lettering may be used on bin labels or shelf tags to separate commonly confused medications. This is particularly useful in high-volume environments where speed and efficiency are important. However, it is important to understand that tall man lettering is not a replacement for proper verification procedures. Pharmacy technicians must still check the full drug name, strength, dosage form, and patient details before dispensing.

Other key examples:

Sample PTCB Exam Questions.

Below you can find three sample PTCB exam questions on the topic of tall man lettering.

These three questions reflect the type of questions that get tested about tall man lettering on the exam – both the style and difficulty. As always, have a go at the questions yourself before comparing your answers with the explanations (in the section below).

Question 1.

What is the primary purpose of tall man lettering in pharmacy practice?

a. To indicate hazardous substances / medicines

b. To highlight dosage differences between medications

c. To reduce errors caused by look-alike, sound-alike drug names

d. To indicate controlled substances

Question 2.

Identify the most accurate application of tall man lettering in practice:

a. PREDNISONE vs. PREDNISOLONE

b. predniSONE vs. prednisoLONE

c. Prednisone vs. Prednisolone

d. prednisone vs. prednisolone

Question 3.

Which statement best describes the role of tall man lettering in medication safety?

a. It replaces the need for double-checking medications

b. It ensures correct dosing for all medications

c. It is one tool used alongside other safety checks to reduce errors

d. It eliminates all risk of look-alike drug errors

Answer Explanations.

Answer to Question 1 – c.To reduce errors caused by look-alike, sound-alike drug names

Tall man lettering is used to reduce the risk of medication errors among drugs that either sound alike or look alike.

Answer to Question 2 – b. predniSONE vs. prednisoLONE

The key factor with this pair of drugs is the suffix – this is the part of the drug name that most increases the risk of selection error.

Answer to Question 3 – c. It is one tool used alongside other safety checks to reduce errors

PTCB exam questions routinely test the function and purpose of tall man lettering as part of a wider strategy to prevent medication errors. Tall man lettering should not be used in isolation, but rather as one of many tools used together to mitigate medication error.

PTCB Cheat Sheet on Tall Man Lettering.

• Definition: tall man lettering uses selective uppercase letters within drug names to highlight differences between look-alike, sound-alike (LASA) medications.
• Purpose: reduces medication errors during prescribing, dispensing, and administration.
• Key idea: only part of the word is capitalised (not the whole name).
• Common examples: predniSONE vs. prednisoLONE, hydrOXYzine vs. hydrALAZINE, cloNIDine vs. clonazePAM.
• Used in: pharmacy computer systems, prescription labels, medication bins, and electronic health records.
• Promoted by: Institute for Safe Medication Practices (ISMP), FDA
• Applies to: high-risk LASA drug pairs known to cause confusion and errors.
• Exam focus: understand why it’s used and how to identify it. Avoid memorising long lists of drug pairs.
• Important: It is a visual aid only, not a replacement for proper checks.
• Always verify: drug name, strength, dosage form, patient details, bar codes, and NDC codes etc.
• Risks: similar drug names can lead to serious patient harm if confused.

Hope you found this week’s PTCB guide to tall man lettering helpful!

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