DTaP-Tdap Mix-Ups Continue to Be Reported

Despite efforts by manufacturers to differentiate between the adult and pediatric formulations of diphtheria, tetanus, and pertussis immunizations, they are ofter improperly administered.

The Institute for Safe Medication Practices (ISMP) Medication Errors Reporting Program database contains numerous cases of mix-ups between adult and pediatric products used to immunize patients against diphtheria, tetanus, and pertussis. Several reports involve errors that affected numerous patients. In one case alone, it was reported that 80 clinic patients were given the wrong vaccine. In all, these mix-ups may be affecting thousands of patients, given that not all cases are reported to ISMP.

Part of the problem is that the official names of the products are very similar, although they are stated in different order on the labels. One of them, diphtheria and tetanus toxoids and acellular pertussis vaccine (DTaP), is sold under the brand names Daptacel and Tripedia (Sanofi Pasteur) and Infanrix (GlaxoSmithKline). This formulation is for active immunization of pediatric patients aged 6 weeks through 6 years. The other vaccine, tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis vaccine (Tdap), is sold under the brand names Boostrix (GlaxoSmithKline) and Adacel (Sanofi Pasteur), and is meant to be used as a booster shot for older children, adolescents, and adults.

These products are easy to confuse due to their similar names and abbreviations. The upper case letters in DTaP correspond with higher antigen quantity of the diphtheria and pertussis components relative to Tdap and its lowercase letters. A larger amount of antigen is needed for initial immunization versus a booster shot. An adult who receives DTaP (higher amount of antigen) would not need to be revaccinated but would be more likely to be sore at the vaccination site. In contrast, an infant/child who receives Tdap would have received a lesser amount of antigen and may not respond adequately. Most reported events have occurred in clinics and physicians’ offices in which the vaccines were chosen from stock supplies, or in hospital settings (especially in emergency departments) in which the vaccines were stored side by side or in the wrong storage area of a refrigerator.

To help prevent this mix-up, separate the pediatric and adult formulations in storage areas. Encourage prescribers to order the vaccines by brand name, not vaccine abbreviation. Consider involving parents or caregivers in the check process. Make them aware of the names of vaccines that are needed by providing them material that details the name and purpose of each vaccine. Ask the parents or caregivers to assist with verification of the vaccine before it is administered.

Many of the errors that are reported have been detected by practitioners when documenting the vaccine information after administration. As this step seems to be effective in detecting these errors, document the vaccine, including lot number, on the vaccine form/log just prior to administration. Do not document actual drug administration until after the vaccine has been given. Identifying differences in lot number format from what is normally recorded could help in recognizing that the wrong product has been selected.

After receiving earlier reports about product mix-ups, Sanofi Pasteur changed the color of the labeling for Daptacel. Additionally, they added statements to the product carton’s front label panels for both Adacel and Daptacel identifying adolescent/adult and pediatric indications, respectively.

Likewise, GlaxoSmithKline has taken steps to differentiate Boostrix and Infanrix to help ensure that they are administered properly. Similar to Sanofi Pasteur, they label prefilled syringes and employ vial caps with a unique color to differentiate each of its vaccines. The packaging for Boostrix includes a statement that the product is for adolescent and adult use.

Although these improvements may have helped, ISMP continues to receive frequent reports of mix-ups. More should be done to enhance vial label text to boldly differentiate between pediatric and adult vaccines. PT

Dr. Gaunt is a medication safety analyst and the editor of ISMP Medication Safety Alert! Community/ Ambulatory Care Edition.

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Pharmacy Times and the Institute for Safe Medication Practices (ISMP) would like to make community pharmacy practitioners aware of a publication that is available. The ISMP Medication Safety Alert! Community/ Ambulatory Care Edition is a monthly compilation of medication-related incidents, error-prevention recommendations, news, and editorial content designed to inform and alert community pharmacy practitioners to potentially hazardous situations that may affect patient safety. Individual subscription price is $52 per year for 12 monthly issues. Discounts are available for organizations with multiple pharmacy sites. This newsletter is delivered electronically. For more information, send an e-mail message to community@ismp.org, or contact ISMP at 215-947-7797.