Don't Confuse Desiccants with Medicine in Cresemba Blister Packs

Published May 2, 2025

Some medicines are more sensitive to changes in humidity and temperature than others. They can lose their effectiveness more quickly if they absorb moisture. Desiccants are used to help prevent this from happening. However, sometimes people have confused a desiccant as a medicine and accidentally ingested the desiccant. We have written about this issue before, but we learned that it has happened again!

Cresemba (isavuconazonium sulfate),a medicine used to treat fungal infections, comes in blister packs (Figure 1) that contain a desiccant to keep the capsules dry. Depending on the dose, a blister pack may contain 5 capsules of Cresemba (74.5 mg each) and a corresponding desiccant, or 7 capsules of Cresemba (186 mg each) and a corresponding desiccant.

Each desiccant blister pack says, "Contains desiccant to protect from moisture. Do not open. Do not eat." But this warning is small and only on one side, so it can be missed. The desiccant itself also says, "DO NOT EAT," but it can be hard to read. Because the desiccant blister looks like a medication blister, a person might accidentally swallow the desiccant thinking it is the medicine if the entire backing is removed (Figure 2).

This happened when a nurse gave both a capsule and the desiccant to a patient, who then swallowed both. The patient felt throat discomfort from the desiccant but suffered no permanent harm.

Here’s what you can do: It's important for healthcare workers and people to know that these blister packs have desiccants that should not be ingested. Pharmacies should consider adding warning labels to the medicine. When picking up the medicine from your pharmacy, ask to speak to the pharmacist. Open the medicine package to look at the blister packs. Ask the pharmacist to point out which blister contains the desiccant and place a sticker or mark over that blister to ensure it is not mistaken as the medicine. When taking the medicine at home, always read the label and take the medicine with the lights turned on so you can see what you are taking.

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