Subtherapeutic posaconazole prophylaxis in a gastric bypass patient following hematopoietic stem cell transplantation

Disclaimer In an effort to expedite the publication of articles related to the COVID-19 pandemic, AJHP is posting these manuscripts online as soon as possible after acceptance. Accepted manuscripts have been peer-reviewed and copyedited, but are posted online before technical formatting and author proofing. These manuscripts are not the final version of record and will be replaced with the final article (formatted per AJHP style and proofed by the authors) at a later time. Purpose A case of invasive fungal infections (IFIs) with subtherapeutic posaconazole prophylaxis in a gastric bypass patient following hematopoietic stem cell transplantation (HSCT) is reported. Summary A 52-year-old malnourished male with a medical history of Roux-en-Y gastric bypass for obesity developed acute myelogenous leukemia and underwent allogeneic HSCT approximately 17 months later. He was admitted 1 month after HSCT for failure to thrive and initiated on parenteral nutrition due to worsening diarrhea and suspected gastrointestinal graft-versus-host disease (GI GVHD). During admission, the patient was continued on daily oral posaconazole for antifungal prophylaxis and was found to have subtherapeutic posaconazole and deficient vitamin levels, likely secondary to his gastrojejunostomy and increased gastric transit time. The oral posaconazole was altered to twice-daily dosing in an effort to increase serum drug levels and prevent IFIs. Conclusion Patients with a history of gastric bypass are at increased risk for malabsorption of oral posaconazole and nutrients, especially following HSCT with suspected GI GVHD.

Unusual Cause of Acute Abdominal Pain in a Roux-en-Y Gastric Bypass Patient

Abdominal pain after Roux-en-Y gastric bypass is an important potential complication. Perforation of an ulcer in the excluded duodenum is a rare occurrence in a patient who has undergone gastric bypass. We present a case of a 61-year-old female with a history of Roux-en-Y gastric bypass, who presented with acute right upper quadrant abdominal pain, which began 1 week after starting treatment with ibuprofen. The evaluation revealed tachycardia, epigastric/right upper abdominal tenderness and leukocytosis. CT abdomen without contrast, ultrasound examination and nuclear medicine scan of the gallbladder were unremarkable. Upper endoscopy revealed an ulcer just distal to her gastrojejunostomy. At exploratory laparotomy, a wellcontained perforation was identified on the anterior duodenal bulb. The perforated ulcer was debrided, the intestine closed with sutures and a drain was left in the abscess cavity. Conventional endoscopic access to bypassed duodenum and stomach is difficult after gastric bypass. In this case, the patient ingested oral ibuprofen and developed both a marginal ulceration as well as an ulceration of the excluded duodenal bulb. The latter finding is consistent with a nonsteroidal anti-inflammatory drug side-effect developing via a hematogenous exposure.