COVID-19 in relation to chronic antihistamine prescription

Abstract

Background Residents with COVID-19 of two external nursing homes received early treatment with an antihistamine and azithromycin. All residents had positive serology for COVID-19 after the first wave, but no hospitalizations or deaths occurred. We assessed whether patients receiving chronic antihistamines in our institution showed lower rates of COVID-19 evolution to severe disease.Methods COVID-19 admissions in the public Hospital of Terrassa (n = 1461) during the pandemic period (March 11th ,2020-May 5th ,2023) and cases (n = 32888) during the period of full suspicion diagnosis (June 1st ,2020-March 23rd ,2022), within the assigned population at the Terrassa Health Consortium in March 2020 (n = 140,681), were analyzed. The infection-hospital admissions and death rates were referred to the number of chronic treatments (nT), including or not antihistamines (AntiHm or NOAntiHm) and the vaccination status before the first infection (VAC or NoVAC), together with gender and age.Results The odds ratio (OD) NoVAC/VAC for infection-hospitalization-death was 1.69-1.83-1.91 respectively (p < 0.0000001). The infection OD increased with the number of chronic treatments NoVAC: 28% (0nT)-48%( > = 6nT) (p = 0.0000001). The OD NoVAC NoAntiHm/AntiHm for infection (1nT) was 1.13 (p = 0.048), hospital admission 2.46 (2-6nT)-1.58 ( > = 7nT) (p = 0.005) and 1.94 for death > = 6nT 1.94 (p = 0.03). [VACNoAntiHm/AntiHm OD for infection = 0.7(1nT); hospital admission = 2.05(2-6nT)-1.46 (> 07nT); death = 1.06(n > 6nT) (p > = 0.05)]. No death occurred in AntiHm patients < = 5nT (vs 0,059% in NoAntiHmNoVAC-0.026%VAC).Conclusions Patients with chronic antihistamine prescriptions, alone or with polypharmacy, showed reduced infection, hospital admission, and mortality rates. This finding is consistent with previous descriptive studies, suggesting the safety of antihistamine treatment and the need to explore its effectiveness in a prospective trial.