Now that sounds promising

"Interestingly, several antihistamine drugs, including clemastine, astemizole, azelastine, brompheniramine, and ebastine, which have been approved for treating allergy symptoms without side effects for decades, have been found to prevent SARS-CoV-2 infection or replication via protein-protein interaction analysis or drug library profiling (30–35). Another study revealed that the use of azelastine was associated with a reduced incidence of SARS-CoV-2 infection based on an analysis of over 219,000 electronic health records"

https://journals.asm.org/doi/10.1128/mbio.01088-24?s=09