Dosing Errors Lead to Noxafil Label Change

Due to dosing errors involving oral posaconazole (Noxafil), the antifungal treatment’s labeling has been revised.

The FDA released a press release today citing dosing errors related to Merck’s 2 oral formulations of Noxafil.

The new labels will indicate that the 2 formulations cannot be directly substituted for each other. Instead, they would require a change in dose. Otherwise, the patient may receive lower or higher levels of the drug needed to treat fungal infections.

The FDA stressed that pharmacists should request clarification from prescribers when the Noxafil dosage form, strength, or frequency is not listed.

In addition, prescribers should make sure to note the correct dosage on all Noxafil prescriptions, and patients should communicate with their health care professionals before they switch between the 2 formulas.

So far, the FDA has received 11 reports of incorrect oral formulas being prescribed or dispensed, including 1 report of a fatality and another report of hospitalization.

“According to the reports, these outcomes were a result of health care professionals not knowing that the 2 oral formulations cannot be substituted for each other without adjusting the dose due to differences in how the medicine is absorbed and handled by the body,” the FDA stated.

Noxafil is available as an oral suspension and delayed-release tablet. It can be used to treat certain fungal infections caused by Aspergillus and Candida. It is also approved as an intravenous solution for injection.

The treatment is indicated for patients who have a greater chance of developing infections because of weakened immune systems.

Health care providers and patients should report adverse events related to Noxafil to the FDA’s MedWatch Safety Information and Adverse Event Reporting Program.