This article is more than 5 years old. Information may no longer be current.
DTaP or Tdap: Vaccine and drug name confusion
Click Here to Manage Email Alerts
Besides the numerous vaccine products, the possibility of confusing many drug products is even greater, as the names of many products are similar, with look-alike or sound-alike names.
Vaccine product mix-ups
In pediatrics, the most common mix-up of vaccine products that has recently occurred has been with diphtheria-tetanus-acellular pertussis (DTaP) products and the relatively newer Tdap vaccine products, Boostrix (GlaxoSmithKline) and Adacel (Sanofi-Pasteur). DTaP is an active immunization product targeting diphtheria, tetanus and pertussis, and is typically first given at 2 months of age. Tdap is typically given at 11 years of age or older as a booster immunization.
The capital letters "D" and "P" in DTaP correspond to increased diphtheria and pertussis antigen concentrations, as compared with Tdap products. Numerous reports of confusion over these products have been made, with inadvertent administration of the wrong product to children (Tdap) and adults (DTaP).
The Institute for Safe Medication Practices (ISMP), a nonprofit organization supporting medication error prevention and safe medication use, has received many reports of mix-ups of these vaccine products, affecting hundreds of patients.
The similarity of the generic names or abbreviations, DTaP and Tdap, has contributed to the confusion.
The product proprietary, or trade, names are not as similar; Infanrix (GlaxoSmithKline), Daptacel (Sanofi-Aventis) and Tripedia (Sanofi-Pasteur) are DTaP products; and Boostrix or Adacel are Tdap products. However, confusion among trade names may also occur, as mix-ups and wrong product administration have been reported for Daptacel and Adacel. Additional factors that are thought to contribute to the confusion include similarity of product packaging, similar storage areas in providers' offices and inpatient hospital pharmacies, and similar product designation and description in patient care computer systems.
To evaluate the epidemiology of pediatric immunization errors, Bundy searched the largest medication database in the United States (Medmarx, United States Pharmacopeia) for 4 years and identified 607 outpatient immunization errors from 149 facilities. The most commonly reported error types were "wrong drug," "extra dose" and "improper dose/quantity." The tetanus and pertussis vaccine products (Tdap, DTaP, Td, DT) had the highest prevalence of vaccine errors. Vaccine errors were also common with pneumococcal vaccines (PCV, PPV).
The CDC provides recommendations in the event of DTaP and Tdap mix-up and inadvertent administration (MMWR. 2006;55:RR-3). If a child younger than 7 years receives Tdap instead of DTaP for any of the three initial series doses, the Tdap dose should not be relied upon, and a dose of DTaP should be given. If Tdap is advertently given to a child younger than 7 years as the fourth or fifth dose of the series, it can be relied upon and a replacement dose of DTaP is not necessary. This child should continue to receive Tdap as an adolescent, as routinely recommended. An adolescent who inadvertently receives DTaP in place of Tdap does not require additional measures. Adverse effects from DTaP administration to an adolescent may be more likely to occur, however, due to the higher antigen content.
Reports of confusion and inappropriate product use or administration have also occurred with other vaccine products. Soon after the tetravalent meningococcal conjugate vaccine, MCV4 (Menactra, Sanofi-Pasteur), was introduced in 2005, numerous reports of subcutaneous administration of this product occurred. Menactra is labeled for intramuscular administration only, unlike the older polysaccharide meningococcal vaccine product (Menomune), which is labeled for subcutaneous use. Mix-ups have also occurred with several varicella virus vaccine products, including inadvertent administration of Zostavax (Merck), an adult vaccine to prevent herpes zoster infection, to infants and children, and administration of Varivax (Merck) to adults. The adult vaccine product, Zostavax, contains a higher concentration of antigen than the pediatric product Varivax. Confusion has also been reported for Varivax and varicella-zoster immune globulin.
Preventing vaccine product mix-ups
Several actions can be used to prevent vaccine confusion and mix-ups.
Pediatric and adult vaccine products can be stored separately in provider offices, medication rooms and pharmacies. One pharmacy department separated infant vaccines from other vaccine products by using a different storage refrigerator, located in a different area of the pharmacy.
It has also been recommended to order vaccines by trade or brand names, and not by generic names.
For example, the trade product names Infanrix and Adacel are more dissimilar, as compared with "diphtheria, tetanus toxoids, and acellular pertussis" (DTaP) and "tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis" (Tdap).
Some drug product ordering programs and drug reference programs list the above pertussis vaccine products similarly, as diphtheria, tetanus and acellular pertussis, as compared with listing “tetanus toxoid” first, as stated on the package labeling for Tdap. It may also help to prompt or require a patient's age when ordering a pertussis vaccine product for a specific patient. Some vaccine manufacturers have changed pertussis vaccine product packaging to help with product differentiation. For example, Adacel highlights "Tdap" and "for adolescent and adult use" on its current package box. For the product Infanrix, "DTaP" is highlighted in a different color on the package box. Once the vial is taken out of the package box, however, product mix-up may still occur, and caution should still be taken before patient administration.
Drug name confusion
With thousands of trade name and generic name drug products commercially available, the risk of confusing one drug product for another is considerably higher than with vaccine products. This topic was the focus of a previous Pharmacology Consult column in October 2008.
Pediatric practitioners can use several means to prevent drug name confusion errors. Listing additional information on medication orders can be helpful, such as both the trade and generic names, and the purpose and use of the medication (eg, "for reflux" when prescribing Zantac [ranitidine]). Use of “tall man” lettering has also been frequently recommended to avoid confusion over sound-alike or look-alike medications. For example, use ZyrTEC to avoid confusion with Zantac, or PriLOSEC to avoid confusion with PROzac.
For more information:
- Bundy DG. Vaccine. 2009;27:3890-3896.
- CDC. MMWR. 2006;55:1016-1017.
- Sauberan JB. Am J Health Syst Pharm. 2010;67:49-57.