Histamine 2 receptor antagonists do not improve the outcomes of hospitalized COVID-19 patients

Introduction
Some observational studies have demonstrated the benefit of famotidine in COVID-19-infected individuals. The preference of using an H2 receptor antagonist (H2RA) over proton pump inhibitors (PPI) during the COVID-19 pandemic has been questioned by clinicians.

Aim
To compare the outcomes of hospitalized patients who were taking H2RA vs. PPI.

Material and methods
We conducted a retrospective review of patients admitted for COVID-19 infection from 1 March until 31 July 2020. We included 396 patients admitted during the study period. Of the total, 39 (9.8%) received H2RA and 86 (21.7%) were taking PPI as home medications; 6 patients were taking both H2RA and PPI.

Results
The baseline characteristics and comorbid conditions were similar in both groups. The mean age was 57.79 ±17.36 years, 43.2% were female, and 48.7% were Caucasian. The common comorbid conditions included HTN (56.8%), obesity (44.4%), diabetes mellitus (38.6%), and coronary artery disease (30.1%). Smoking was more prevalent in the PPI group (42.5% vs. 18.2%, p = 0.03). Gastrointestinal symptoms were seen on initial presentation in 31.1%, and 43.9% had elevated liver enzymes. The H2RA group had similar mortality (HR = 0.84, 95% CI: 0.35–2.05) to the non-H2B group. It remained non-significant as compared to PPI (HR = 0.34–3.19, 95% CI: 0.34–3.19). The secondary outcomes including readmission, ICU admission, and severe COVID infections (including ARDS and thromboembolism) were similar in these groups.

Conclusions
The H2 receptor antagonist used as a home medication did not show benefit over the PPI in patients admitted for COVID-19 infections.