Published December 1, 2025
A person with a GI (gastrointestinal) infection (C. diff) was given a prescription for Firvanq (vancomycin) oral solution. This medicine comes as a kit with two bottles: one with vancomycin powder (medicine) and one with liquid (diluent) for mixing (Figure 1). Before giving it to the patient, the powder and liquid should be mixed together. In this case, the pharmacy dispensed the kit without the medicine being mixed. At home, the person took “doses” from the liquid bottle which did not have the medicine in it. As a result, the person’s infection got worse and turned into a severe life-threatening infection (sepsis),and they had to go back to the hospital.
The name Firvanq is printed on both bottles—the powder (medicine) and the liquid (diluent). In the past, we have heard of pharmacy staff seeing the drug name on the liquid bottle label and thinking it was the medicine. So, they gave out just the liquid bottle by mistake. Because of these mistakes, the company changed the label on the liquid bottle. Now, the word “Diluent” (which means liquid for mixing) is bigger, and the Firvanq drug name is smaller. There is also a warning that states “DO NOT DISPENSE THIS BOTTLE TOTHE PATIENT.” This may help pharmacy staff realize the bottle only contains the liquid diluent. But if the liquid bottle is given to patients by mistake, they might not know what “diluent” means and think it is the actual medicine.
Here's what you can do: If you are prescribed a new medicine, ask your healthcare provider about the medicine. Learn the name of the medicine, what it is being used to treat, how and when it should be taken, and what side effects to expect. Ask how long you need to take the medicine and when you should see that it is working (or not working).
When picking up the medicine, always ask to speak to the pharmacist. Open the bag and look at the medicine and the labels to make sure the medicine is for you and it is what you expect (e.g., read the label to make sure it does not state “DILUENT” or “DO NOT DISPENSE THIS BOTTLE TO THE PATIENT”). If it is a liquid medicine, ask the pharmacist for a measuring device and how you should measure each dose. Then, using the device, show the pharmacist how you will measure a dose.
As in the case above, with Firvanq, you may not know if the (powder) medicine was mixed into the liquid. However, if you are just given the powder, do not add liquid yourself. In addition, if you are given both the powder and liquid bottles, do not mix them yourself. Bring it back to the pharmacy to have it mixed.
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