Background Clinical manifestations of sarcoidosis vary widely, depending on the intensity of the inflammation and the organ systems affected. So far, no curative treatment exists; the disease can only be suppressed. All treatment options cause side effects affecting quality of life. The aim of this study was to establish and rank the prevalence of self-reported gastrointestinal side effects of drugs used in the treatment of sarcoidosis. Methods A cross-sectional web-based anonymous survey about complaints and side effects was conducted among sarcoidosis patients in the Netherlands, United Kingdom, and United States of America. Results Of the participants, 70% were being treated with one or more drugs. The most important reported side effect was weight gain, associated with increased appetite among prednisone users (as monotherapy as well as in combination with other drugs). Methotrexate (MTX) users especially experienced nausea, with monotherapy as well as combination therapy. Vomiting and weight loss were most prominent among azathioprine and mycophenolate mofetil (MMF) users, whereas diarrhoea was frequently mentioned by MMF and MTX users. The reported side effects of hydroxychloroquine were generally rather mild. Conclusion The current study ranked the gastrointestinal side effects associated with pharmacotherapy in sarcoidosis patients. Pharmacotherapy does have multiple gastrointestinal side effects. The strongest association between a reported side effect and drug use was that of weight gain associated with increased appetite among prednisone users. It would therefore be useful for future research to look further into dietary interventions to counter these side effects and reduce their burden.Publisher's Note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

PurposeIdiopathic pulmonary fibrosis (IPF) is an inexorably progressive disease, which has a great impact on patients’ lives. Pirfenidone and nintedanib are approved and recommended antifibrotic drugs for patients with IPF. The aim of this study was to evaluate self-reported gastrointestinal side effects of antifibrotic drugs in 176 Dutch IPF patients.MethodsA cross-sectional web-based anonymous survey about complaints and side effects was conducted among IPF patients in the Netherlands. Logistic regression was used to quantify whether pirfenidone and nintedanib caused complaints of nausea, vomiting, diarrhoea, appetite loss, weight loss or loss of taste or smell perception.ResultsThe questionnaire was completed by 176 IPF patients, 71 of whom used pirfenidone and 85 nintedanib, while 20 patients did not use any antifibrotic drugs. Nintedanib users reported complaints of diarrhoea, vomiting, weight loss and loss of appetite (p < 0.01). Nausea was a significant adverse reaction (p < 0.05). Pirfenidone caused increased appetite loss (p < 0.01) and the risk of weight loss (p < 0.05). The increase in loss of appetite and weight loss did not differ significantly between the two drugs.ConclusionThe current study showed that nintedanib causes a significant increase in diarrhoea, vomiting, weight loss and loss of appetite, while pirfenidone led to loss of appetite. Our results suggest new avenues regarding dietary recommendations for IPF patients.