Confusion with Fetroja preparation instructions
Apharmacist noticed that the preparation instructions on the carton for Fetroja (cefiderocol), a cephalosporin antibacterial indicated in patients 18 years of age or older for the treatment of complicated urinary tract infections caused by susceptible Gram-negative microorganisms, did not match the preparation instructions in the package insert. The vial stated that there is 1 g per vial. The package insert stated to reconstitute a 1 g Fetroja vial with 10 mL of diluent, which would result in a volume of approximately 11.2 mL of reconstituted solution. To provide a 750 mg dose, 8.4 mL should be withdrawn from the reconstituted vial (final concentration of 0.089 g/mL [89 mg/mL], as noted in the package insert), and then further diluted in a 100 mL infusion bag (see Fetroja package insert).
However, when the error was reported to ISMP, the Fetroja carton label stated that once the 1 g vial is reconstituted with 10 mL of diluent, the resultant concentration is 0.1 g/mL (100 mg/mL) (see Fetroja carton preparation, top). If the volume withdrawn from the reconstituted vial is based on the concentration specified on the carton, this could result in an underdose. So, if referring to the 0.1 g/mL (100 mg/mL) concentration specified on the carton for a 750 mg desired dose, 7.5 mL would be withdrawn, which would only provide 670 mg or about 10% less than intended dose. Underdosing antimicrobials such as Fetroja could potentially lead to treatment failures.
The manufacturer, Shionogi, has confirmed that the concentration on the carton was incorrect and that the package insert contains the correct preparation instructions. The correct concentration, rounded to 0.089 g/mL (89 mg/mL), following reconstitution of the vial now appears on the current carton (see Fetroja carton preparation, bottom).
Cometriq listed on discharge form instead of CoQ10
While reviewing a discharge medication form during medication reconciliation, a patient's primary care physician noted that a COMETRIQ (cabozantinib) 100 mg oral daily dose was incorrectly added to the discharge medication list instead of a coenzyme Q10 (CoQ10) 100 mg oral daily dose. Cometriq is a tyrosine kinase inhibitor indicated to treat patients with progressive, metastatic medullary thyroid cancer. While hospitalized, the patient's own supply of CoQ10, an over-the-counter supplement, was correctly administered. Thankfully, a prescription was not sent to the pharmacy, so the patient never received the wrong drug and likely would not qualify for insurance coverage given the lack of an appropriate diagnosis. The two products share overlapping characteristics. Both names start with the letters "c-o" and contain a "q," and both are prescribed in similar 100 mg dosages. For example, Cometriq is available in a 100 mg daily-dose carton containing a combination of 80 mg and 20 mg capsules, while CoQ10 is available as 100 mg capsules.
The pharmacy staff was notified about the mix-up. After the medication error was brought to the hospital's attention, the Cometriq order was removed from the patient's electronic health record. ISMP had planned to notify the manufacturer, Exelixis, and the US Food and Drug Administration (FDA) about the confusion.