Breakthrough invasive fungal infection in an immunocompromised host while on posaconazole prophylaxis: an omission in patient counseling and follow-up.

Posaconazole (Noxafil (Schering-Plough Corporation) is a triazole antifungal approved in the United States for the treatment of oropharyngeal candidiasis and for the prophylaxis of Candida and Aspergillus infections in the immunocompromised host. Posaconazole is available only as an oral suspension. When used for the prevention of Candida and Aspergillus infections, posaconazole should be taken three times daily with a high fat meal to maximize oral absorption. Failure to take posaconazole with food will lead to subtherapeutic serum levels and decreased clinical effectiveness of the drug.We report the case of a 49-year-old woman with acute myeloid leukemia who received 4 months of posaconazole as an outpatient for the labeled indication of prophylaxis of Candida and Aspergillus infections. During her last admission, the patient presented with an invasive sinus infection diagnosed as a mixed Aspergillus and Mucor etiology. The patient succumbed to this infection five weeks after presentation. Upon investigation it was found that the patient did not self-administer posaconazole as required in the product labeling, which may have led to drug failure in this patient. We submit this case to illustrate the importance of patient education regarding proper administration of posaconazole. The important role of the outpatient physician, nurse, and pharmacist in this setting is underscored.