A specialty pharmacy was preparing a refill for Entyvio® (vedolizumab) 300 mg vial for intravenous (IV) injection. Entyvio is a humanized monoclonal antibody that is used to treat Crohn’s disease and ulcerative colitis. During pre-verification for the refill, the pharmacist noticed the dispensed quantity was two, with the directions to inject 300 mg (1 vial) IV on week zero, two, six, and then every eight weeks thereafter. Looking at the dispensing history, the pharmacist discovered that the pharmacy had previously dispensed one fill of two vials (for weeks zero and two) and a second fill of two vials (for week six). The pharmacist identified an error with the second fill: the pharmacy should have dispensed only one vial for week six, which would have been a 56-day (or eight week) supply. The pharmacist called the infusion center that administered the medication, and the infusion center staff confirmed they still had one vial on hand for the next infusion (due eight weeks after the dose given on week six). The refill order was canceled. 

Many specialty medications used for auto-immune conditions have a different dosing frequency for induction doses than the maintenance doses. For this pharmacy, the dispensing system automatically populated the refill quantity to be the same quantity and days’ supply as was dispensed for the previous fill.  

The Institute for Safe Medication Practices (ISMP) surveyed 27 specialty pharmacies in 2021 to learn about medication quantity and package size errors. One of the most common types of errors reported were those related to confusion with induction doses. To reduce the risk of errors with induction doses, add dispensing software notes to alert staff about correct dispensing procedures for applicable medications. Consider entering two prescriptions into the dispensing software for medications that change frequency over time: enter one prescription for induction doses and one prescription for maintenance doses. Dispense the induction dose prescription first, and when it is completed, dispense the maintenance dose prescription.