Mirtazapine treatment of diabetic gastroparesis as a novel method to reduce tube-feed residual: a case report

INTRODUCTION: Gastroparesis is a common motility disorder that is characterized by delayed gastric emptying in the absence of mechanical obstruction. Diabetes, along with other neuromuscular and infiltrating disorders, can predispose individuals to an increased risk of developing gastroparesis. Gastroparesis can be easily diagnosed through gastric emptying studies but is usually difficult to successfully treat. Therapy usually begins with pro-kinetic and anti-emetic agents. CASE PRESENTATION: Our patient was an 87-year-old African-American woman who was a nursing home resident, with a history of diabetes mellitus type 2 and subarachnoid hemorrhage leading to aphasia, hemiplegia, seizures and dysphagia requiring percutaneous gastric feeds. While at the nursing home, she had recurrent aspiration pneumonia and large tube-feed residuals consistent with a diagnosis of underlying gastroparesis. Her management included metoclopramide and reduced tube-feeding rates, which improved her symptoms. However, within months the aspiration and increased residuals returned. After trials of different medication therapies without success, she started mirtazapine and her residual volume and aspirations decreased with a dose of 15mg nightly. CONCLUSION: In patients with gastroparesis recalcitrant to first line therapies such as metoclopramide, off-label use of mirtazapine may provide adequate non-invasive management of gastroparetic symptoms.