Introduction: Famotidine is a competitive histamine H2-receptor antagonist most commonly used for gastric acid suppression but thought to have potential efficacy in treating patients with COVID-19 . The aims of this systematic review and meta-analysis are to summarize the current literature and report clinical outcomes on the use of famotidine for treatment of hospitalized patients with COVID-19.
Methods: Five databases were searched through February 12, 2021 to identify observational studies that reported on associations of famotidine use with outcomes in COVID-19 . Meta-analysis was conducted for composite primary clinical outcome (e.g . rate of death, intubation, or intensive care unit admissions) and death separately, where either aggregate odds ratio (OR) or hazard ratio (HR) was calculated .
Results: Four studies, reporting on 46,435 total patients and 3,110 patients treated with famotidine, were included in this meta-analysis . There was no significant association between famotidine use and composite outcomes in patients with COVID-19: HR 0.63 (95% CI : 0.35 , 1.16). Across the three studies that reported mortality separated from other endpoints, there was no association between famotidine use during hospitalization and risk of death - HR 0.67 (95% CI : 0.26 , 1.73) and OR 0.79 (95% CI : 0.19 , 3.34). Heterogeneity ranged from 83.69% to 88.07% . Conclusion: Based on the existing observational studies, famotidine use is not associated with a reduced risk of mortality or combined outcome of mortality, intubation, and/or intensive care services in hospitalized individuals with COVID-19, though heterogeneity was high, and point estimates suggested a possible protective effect for the composite outcome that may not have been observed due to lack of power . Further RCTs may help determine the efficacy and safety of famotidine as a treatment for COVID-19 patients in various care settings of the disease