Nintedanib-Induced Colitis Treated Effectively With Budesonide

A 68-year-old male with a past medical history of interstitial pulmonary fibrosis (IPF) on nintedanib and chronic nintedanib-induced diarrhea for three years presented with hematochezia and worsening diarrhea. Diarrhea had persisted despite the use of cholestyramine and oral antidiarrhea medications. As part of the evaluation of diarrhea, he had undergone colonoscopy two years prior, which had shown non-specific moderate diffuse colitis. No significant abnormalities had been noted on physical exam and lab tests. On the present admission, colonoscopy showed diffuse erythematous, friable, and granular mucosa throughout the entire colon. Biopsies were taken and pathology was reported as acute superficial inflammation and possible nintedanib-induced colitis. Since the patient wanted to continue nintedanib as a part of IPF treatment, 9 mg oral budesonide was started, and the patient was followed up after four months. At his follow-up visit, the patient reported that diarrhea had completely resolved. In this report, we illustrate and discuss a case of nintedanib-induced colitis, which can be resistant to oral antidiarrhea medication and cholestyramine. The mechanism of this side effect is not completely understood; however, it may be related to direct inflammation of the intestinal epithelium, given that nintedanib metabolites are excreted primarily in the stool. As a result, it has been hypothesized that steroids could potentially treat this diarrhea by relieving this inflammation. In our patient, we elected to use budesonide due to less associated systemic side effects and possible similarity of inflammation between nintedanib-associated colitis and inflammatory bowel disease.