Abstract: Received: 16 August 2021 | Accepted: 1 October 2021 DOI: 10.1002/jmv.27375 SHORT COMMUNICATION The association between famotidine and in‐hospital mortality of patients with COVID‐19 Toshiki Kuno1,2 | Matsuo So2 | 1 Division of Cardiology, Montefiore Medical Center, Albert Einstein College of Medicine, New York, New York, USA Mai Takahashi2 | Natalia N. Egorova3 Abstract Famotidine has been considered to be a potential treatment for COVID‐19 but the 2 Department of Medicine, Icahn School of Medicine at Mount Sinai, Mount Sinai Beth Israel, New York, New York, USA 3 Department of Population Health Science and Policy, Icahn School of Medicine at Mount Sinai, New York, New York, USA current data is conflicting. This retrospective study was conducted by utilizing data of 9565 COVID‐19 hospitalized patients. Patients treated with and without famotidine were matched by propensity score using a 1:1 matching scheme. A total of 1593 patients (16.7%) received famotidine. In‐hospital mortality was similar in patients treated with and without famotidine in the propensity‐matched cohorts Correspondence Toshiki Kuno, MD, PhD, Division of Cardiology, Montefiore Medical Center, Albert Einstein College of Medicine, 111 East 210th St, Bronx, NY 10467‐2401, USA. Email: tkuno@montefiore.org (28.3% vs. 28.2%, p = 0.97), which remains similar irrespective of severity or concomitant treatment by steroids. Famotidine treatment was not associated with a lower risk of in‐hospital mortality of COVID‐19 patients. KEYWORDS COVID‐19, famotidine Famotidine has been considered to be a potential treatment for 1, 2020 and March 30, 2021.7–10 Patients were divided into two COVID‐19 since the pandemic started in 2020. Since the hypothesis groups, those with and those without treatment with famotidine. derives from the concept that severe acute respiratory syndrome The primary outcome was in‐hospital mortality. Patients coronavirus 2 infections can cause histamine release via mast cell treated with famotidine and without famotidine were matched by activation, which leads to systemic inflammation and cytokine re- propensity score using a 1:1 matching scheme without replace- lease, it has been expected that famotidine can reduce systemic in- ment. Good balance (standardized mean difference < 0.10) was flammation and cytokine release.1 Nonetheless, it remains uncertain achieved for patients' baseline characteristics including age, sex, whether famotidine is effective for the treatment of COVID‐19.1 comorbidities, vital signs at admission, laboratory data, and in‐ While some observational studies showed potential benefit of fa- hospital treatment including the use of steroids, interleukin‐6 motidine by decreasing mortality due to COVID‐19,2,3 another study (IL‐6) inhibitor, convalescent plasma, and remdesivir. As a sensi- demonstrated no benefit of famotidine.4 In addition, we hypothe- tivity analysis, we performed inverse probability treatment sized that steroids treatment which is the standard treatment of weighted (IPTW) analysis. In addition, multiple imputations for COVID‐19 as of May 15, 2021, might mitigate the effect of famoti- missing data were conducted (R software MICE package). dine since steroids also reduce inflammation and cytokine release through mast cells.5,6 We performed several analyses where we investigated the effect of famotidine on different subgroups of patients. We compared in‐ The aim of this study was to..