Noxafil Dosing Error Warning Issued By FDA

Government health officials are warning users of the antifungal medication Noxafil to be cautious when substituting the two oral formulations for one another, due to a potential risk of dosing errors that could cause patients to suffer from over or under dosage. 

A Noxafil warning notice was issued by the FDA on January 4, after consumer reports indicated users alternated between two forms of the medication at equal milligram dosages, but still suffered from dosing complications.

To date, the FDA is aware of at least 11 reports involving Noxafil problems, including at least one hospitalization and one fatality as a result of alternative form dosage complications.

Noxafil is a prescription medication that is used to help prevent certain invasive fungal infections caused by fungi called Aspergillus and Candida. Noxafil oral suspension can also be used to treat a fungal infection called thrush, which is a condition caused by Candida infections in the mouth or throat areas. Patients who are prescribed the medication have an increased risk of getting these fungal infections due to their weakened immune systems.

Over or under dosing a patient with a serious fungal infection could cause severe and life changing outcomes such as pain, swelling, need for surgery, loss of infected areas, poisoning dangers and even death.

Noxafil can be prescribed in either its original form, oral suspension, or in the form of a delayed-release tablet. According to the FDA, since 2013, when the delayed release tablet was introduced into the medicine field, 11 reports of wrong oral formulations being prescribed or dispensed to patients were reported. Of the 11 reports, one fatality and one hospitalization occurred as a result of dosage complications.

According to the FDA, an investigation revealed that substituting the two oral formulations, even when milligrams dosage is kept the same, can cause patients to suffer from drug levels that are lower or higher than needed or intended to effectively treat the fungal infections. The reasoning is due to the way each form of medication is absorbed, broken down, and handled by the body.

An investigation by the drug manufacturer, Merck, and the FDA, further discovered that healthcare professionals were not aware that the two formulations could not be substituted with equal dose prescriptions and that there were not any warnings or indicators on or within the medicines packaging.

In addition to the FDA’s warning and changing the outer carton of Noxafil, Merck has revised the drug labels to indicate that the two oral formulations cannot be directly substituted for each other and require a change in dose.

Due to the changes, prescribers should be very specific when detailing dosage form, strength, a frequency on all prescriptions they write for Noxafil. Pharmacists are being instructed to request clarification from prescribers when any of the medications specifics are either undeterminable or not listed. Patients currently using Noxafil medications are encouraged to contact their prescribing doctors for additional information before alternating oral formulations.