A 30-year-old man suffered a gunshot wound to the abdomen. He had a difficult postoperative course because of fecal spillage. By the second postoperative day he developed a low-grade fever. Abdominal CT scanning showed a pancreatic pseudocyst, assumed to be secondary to retroperitoneal trauma. He was started on intravenous imipenem-cilastatin. On the third day of antibiotic therapy, while his teperature continued to remain elevated, 200 mg/d intravenous fluconazole was added empirically. The fever continued unabated and on the ninth post-antibiotic day two sets of blood cultures (obtained the day before) reported growth of Candida species. The most appropriate antifungal agent for this patient would be:.