Decrease of voriconazole trough levels during therapy with enteral nutrition: a case report

BACKGROUND: Voriconazole (VRCZ) is the first-line therapy for chronic pulmonary aspergillosis and is available in both intravenous and oral formulations. The bioavailability of the oral form is estimated to be over 90% in healthy volunteers. Some drugs are reported to interact with enteral nutrition (EN), but there are few reports about the trough levels of VRCZ during EN therapy. Here, we describe changes in the VRCZ trough levels in a patient receiving continuous EN therapy. CASE PRESENTATION: The patient was a 58-year-old man with esophageal cancer and a history of partial pulmonary resection due to aspergilloma. He was taking oral VRCZ tablets and his VRCZ trough level was about 2 μg/mL before esophageal cancer surgery. Following esophagectomy, VRCZ was restarted on postoperative day 16. Crushed VRCZ tablets were administered via a jejunostomy tube because of swallowing difficulty. He was also receiving EN, which was interrupted only during the administration of VRCZ. When we checked his VRCZ level 5 days after restarting VRCZ, the trough level was 0.80 μg/mL. After increasing the VRCZ dose, reducing EN, and changing the administration route from jejunostomy tube to oral, his trough level increased to 1.87 μg/mL. CONCLUSIONS: A decrease in the VRCZ trough level was observed when VRCZ was administered via a jejunostomy tube while the patient was receiving continuous EN. Careful monitoring of VRCZ levels is needed in such cases. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s40780-021-00237-4.