FDA Advise-ERR: Medication errors associated with Taxotere and Taxol

PROBLEM: The FDA MEDWATCH program has identified three types of errors involving TAXOTERE (docetaxel) and TAXOL (paclitaxel). Confusion between these two drugs can result in serious adverse outcomes since they have different dosing recommendations and uses in various types of cancer. First, look-alike and sound-alike confusion has resulted in errors. Recently, a physician ordered, "Taxol 175 mg/m² x 1.5 m² = 260 mg." A pharmacist prepared Taxotere 260 mg in error. The patient's nurse did not notice the mistake and started the infusion. The patient received about 183 mg or 122 mg/m² before a physician noticed that the infusion container was labeled Taxotere. The patient's death five days later could not be linked to the error since he was debilitated with metastatic disease. In another case, a physician ordered Taxotere 120 mg IV over one hour, but the pharmacy prepared Taxol 120 mg in error. After the dose was administered, a nurse noticed that the label said, "paclitaxel," not "Taxotere." The error occurred even though the container was checked by at least 3 professionals.

In addition to name confusion, twenty-one reports have been received regarding errors in the reconstitution of Taxotere due to overfill in the drug vial and the enclosed diluent vial. Taxotere 20 mg and 80 mg vials contain 23.6 mg and 94.4 mg of docetaxel respectively due to the overfill volumes. The diluent vials also contain overfill. Taxotere requires two dilutions prior to administration. First, the diluent must be added to the Taxotere for injection concentrate. Next, the Taxotere solution must be further diluted in an infusion bag. The final strength could be miscalculated if the actual amounts contained in the drug vials are used rather than 20 mg and 80 mg of docetaxel.

Finally, three practitioners have reported concern about the packaging and labeling similarity between the 30 mg and 100 mg Taxol cartons. A wrong dose could be selected since the new 30 mg cartons, which were smaller in the past, are now the same size and color as the 100 mg cartons. Both the 30 mg and 100 mg cartons contain 6 mg/mL of paclitaxel, as does a 300 mg/50 mL vial.

SAFE PRACTICE RECOMMENDATIONS: When ordering Taxol or Taxotere, confusion can be averted if prescribers print brand and generic names on the prescription orders since the generic names do not look similar. If handwritten prescriptions are difficult to read, pharmacists should confirm the drug name with prescribers. If the confirmation is conducted verbally, the drug name must be spelled since the generic names can sound similar. Preprinted order forms can also help by clearly communicating the desired medication. Pharmacy labels and preprinted order forms should list both the generic and brand names, and upper and lower case fonts should be used to distinguish between TaxOL and TaxOTERE or PACLItaxel and DOCEtaxel. Two pharmacists should provide independent confirmation before chemotherapy is dispensed and two nurses should ensure that the correct drug has been dispensed for the correct patient before administering the medication. Computer systems that alert staff when doses go beyond 100 mg/m2 provide added safety, and would prevent Taxotere overdoses like the one above.

When reconstituting Taxotere for injection concentrate, add all of the enclosed diluent and write the resultant concentration, 10 mg/mL, on the vial so that the proper dose will be withdrawn for further dilution in a 250 mL infusion bag. Although the fill strengths, 23.6 mg and 94.4 mg for the 20 mg and 80 mg docetaxel, are listed on the label, do not use these fill strengths when reconstituting the drug. These overfills are commonly used in drug vials to ensure that users can withdraw the intended volume from the vial and are not intended for reconstitution calculations. Instead, follow the package insert directions. The manufacturer, Aventis, is revising the package insert and the carton label to clarify the dilution and reconstitution directions.

To avoid selecting the wrong size Taxol containers, physically separate the storage of the two products in the pharmacy. If possible avoid stocking multiple sizes. The manufacturer, Bristol-Myers Squibb Company, is redesigning the label to differentiate the 30 mg and the 100 mg cartons. Paclitaxel is also available from Ivax as ONXOL.

FDA Advise-ERR is provided by the Office of Post-Marketing Drug Risk Assessment, U.S. Food and Drug Administration