Drug Name Confusion: why you need professional naming
original article by Kathleen Doheny on Medscape Medical News / Drug Name Confusion: More Than 80 New Drug Pairs Added to the List - Medscape - Aug 08, 2023 and edited by pharmanaming.com
Drug names can look or sound like other drug names, which leads to confusion and potentially harmful medication errors. While non proprietary drug names hardly lead to confusion as the WHO approval process is very strict, brand (proprietary) names can lead to confusion.
Examples of the numerous drug names that have been confused because they look and/or sound similar include Celebrex® (celecoxib), Cerebyx® (fosphenytoin), and Celexa® (citalopram). Factors such as poor handwriting and clinical similarity may exacerbate the problem.
This problem can be alleviated through actions by regulatory agencies, pharmaceutical manufacturers, healthcare professionals, and patients. To address the problem, significant changes in the pharmaceutical regulatory process have occurred in the US and Europe.
Zolpidem (Ambien) is a well-known sedative for sleep. Letairis (Ambrisentan) is a vasodilator for the treatment of pulmonary arterial hypertension. Citalopram (Celexa) is an antidepressant; escitalopram (Lexapro) is prescribed for anxiety and depression.
Those are just four of the more than 80 pairs of drug names that the Institute for Safe Medication Practices (ISMP) recently added to its list of confusing drug names. The aim is to increase awareness about the potential for a serious medication mistake when the wrong drug is given because of drug names that look and sound similar.
This prescription for clonazepam was misinterpreted and dispensed as lorazepam.
Awareness of these drug names, however, is just the first step in preventing medication mistakes. Healthcare providers should take a number of other steps as well, experts said.
ISMP launched its confusing drug names list, previously called look-alike, sound-alike (LASA) drugs, in 2008. The new list is an update of the 2019 version, which focuses on the prevention of medication mistakes. The new entries were chosen on the basis of a number of factors, including ISMP's analysis of recent medication mishap reports that were submitted to it.
The ISMP list now includes about 528 drug pairs. The list is long, he said, partly because each pair is listed twice, so readers can cross reference. For instance, hydralazine and hydroxyzine are listed in one entry in the list, and hydroxyzine and hydralazine are listed in another.
Professional naming agencies like pharmanaming.com incorporate the information on the confusing drug names into their proprietary algorithm and use it when developing brand names for drugs.
Xanax versus Zantac as example of confusing drug brand names
Confusing Drug Names: Ongoing Issue
The length of the list, as well as the latest additions, are not surprising, said Mary Ann Kliethermes, PharmD, director of medication safety and quality for the American Society of Health-System Pharmacists, a membership organization of about 60,000 pharmacists who practice in inpatient and outpatient settings.
"I've been in practice over 45 years," she said, "and this has been a problem ever since I have been in practice." The sheer volume of new drugs is one reason, she said. From 2013 through 2022, the US Food and Drug Administration (FDA) approved an average of 43 novel drugs per year, according to a report from its Center for Drug Evaluation and Research. "Since the 90's, this [confusion about similar drug names] has happened," Kliethermes said.
According to a 2023 report, about 7000 to 9000 people die each year in the US as the result of a medication error. However, it's impossible to say for sure what percentage of those errors involve name confusion.
Not all the mistakes are reported. Some that are reported are dramatic and deadly. In 2022, a Tennessee nurse was convicted of gross neglect and negligent homicide. She was sentenced to 3 years' probation after she mistakenly gave Vercuronium, an anesthetic agent, instead of the sedative Versed to a patient, and the woman died.
Updated List: A Closer Look
Many of the new drug pairs that are listed in the update are cephalosporins, said Kliethermes, who reviewed the new list for Medscape Medical News. In all, 20 of the latest 82 additions are cephalosporins. These include drugs such as cefazolin, which can be confused with cefotetan, and vice versa. These drugs have been around since the 1980s, she said, but "they needed to be on there." Even in the 1980s, it was becoming difficult to differentiate them, and there were fewer drugs in that class then, she said.
Influenza vaccines made the new list, too. Fluzone High-Dose Quadrivalent can be confused with fluzone quadrivalent. Other new additions: hydrochlorothiazide and hydroxychloroquine, Lasik and Wakix, Pitressin and Pitocin, Remeron and Rozerem.
Beyond the List and recommendations
While it's not possible to pinpoint how big a problem name confusion is in causing medication mistakes, a variety of practices can reduce that risk substantially:
Tall-man lettering.
Both the FDA and the ISMP recommend the use of so-called tall-man lettering (TML), which involves the use of uppercase letters, sometimes in boldface, to distinguish similar names on product labels and elsewhere. Examples include vinBLAStine and vinCRIStine.
Electronic prescribing.
It eliminates the risk of handwriting confusion, however, electronic prescribing can have a downside. When ordering medication, a person may type in a few letters and may then be presented with a prompt that lists several drug names, and it can be easy to click the wrong one. For that reason, ISMP and other experts recommend typing at least five letters when searching for a medication in an electronic system.
Use both brand and generic (INN) names on labels and prescriptions.
Write the indication.
That can serve as a double check. If a prescription for Ambien says: "For sleep," there's probably less risk of filling a prescription for ambrisentan, the vasodilator.
Smart formulary additions.
When hospitals add medications to their formularies, part of that formulary assessment should include looking at the potential risk for errors. This involves keeping an eye out for confusing names and similar packaging. Do that analysis up front and put in strategies to minimize that. Maybe you look for a different drug [for the same use] that has a different name. Or choose a different manufacturer, so the medication would at least have a different container.
Use bar code scanning.
Suppose a pharmacist goes to the shelf and pulls the wrong drug. Bar code scanning provides the opportunity to catch the error. Many community pharmacies now have bar code scanning. ISMP just issued best practices for community pharmacies, Gaunt said, and these include the use of bar code scanning and other measures.
Access the list.
The entire list is on the ISMP site and is accessible after free registration.
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