Cisplatin or carbaplatin? Prednisone or prednisolone? Similarities between many drug names are a source of continuing confusion and medication errors. One method to reduce this confusion is “tall man lettering,” using capital letters, or bold face, or another color, to distinguish the different parts of two similar drug names. PredniSONE and prednisoLONE, for example.
In 2001, the FDA requested that makers of 16 generic drugs with look-alike names use tall man lettering on labeling, according to Michael Cohen, RPh, MS, FASHP, president of the Institute for Safe Medication Practices (ISMP). ISMP has a longer list of look-alike names that it recommends be given the tall man treatment, Cohen says. Cohen is a member of the Drug Topics Editorial Advisory Board.
But does using capitals or boldface really help differentiate look-alike drug names or preventing errors? No, says Bruce L. Lambert, PhD, director of the Center for Communication and Health and professor at Northwestern University School of Communication. “There is no evidence that tall man reduces the rate of drug confusion errors in a real clinical practice setting. None,” he tells Drug Topics.
Although several studies have been done in simulated circumstances rather than real pharmacies, the results have been mixed, Lambert notes, which Cohen agrees with. Results appear to depend on whether studies were done on health professionals or laypeople and other factors. The biggest study done in real-world circumstances was conducted in children’s hospitals over nine years and found no significant reduction in medication errors after tall man lettering was introduced.
That study had flaws, says Lambert, but it shows no benefits in a real clinical setting. “It’s not a perfect study, but it still is the only really good large-scale study we have,” he says.
Cohen says more analysis would be good. “I would love to see a real-world study where they go into pharmacies and look at whether or not people choose the wrong item.”
More Differentiation Needed
With tall man lettering, some efforts just capitalize parts of the name when more should be done, says Cohen. The drug name should include “anything you can do—color, underlining, italics, background—to make those letter characters stand out so that it catches people’s attention,” he says.
And it is not just about labeling, Cohen says. Databases and electronic prescribing systems should be amended to use as many ways as possible to differentiate look-alike names.
One of advantage of tall man lettering is that it is inexpensive. Labels costs little, and making changes to databases might have some costs at first due to new programming, but not much, Cohen notes.
There are few downsides to using tall man lettering. The biggest, according to Lambert, is that it can confer a false sense of security that enough has been done. “Everyone’s doing tall man because it’s cheap and easy, but you’d better keep measuring your error rate, you’d better keep doing other things, because . . . if you’ve just implemented tall man, that’s not enough.”
Barcoding is one of the best ways to help keep from confusing two similarly named drugs, both Cohen and Lambert say. “So as long as the name is entered correctly, and the order is processed, the pharmacist is going to scan in the container and get an error message,” Cohen says.
Using indication alerts would also cut down on drug confusion, Lambert says. If the EHR alerts that a drug being prescribed does not match a patient’s disease or condition, it could prevent a patient from getting a vial of hydralazine rather than hydroxyzine, he says.