It's part of the standard practice that was submitted here earlier:

https://www.evms.edu/covid-19/covid_care_for_clinicians/#d.e...

I was surprised about the famotidine, I had not heard much about that being used:

https://hartfordhealthcare.org/about-us/news-press/news-deta...

I'd heard about ranitidine, but that was taken off the market (for unrelated reasons). Famotidine is in the same family - in fact it's what I take now - so makes sense I guess.

Also: the proton-pump inhibitors (xyz-azole) that constitute the other main family of chronic-heartburn medications have apparently been associated with a significant increase in COVID-19 mortality.