What’s the famotidine dose for MCAS?

I’m on loratadine 10mg twice a day and have just started famotidine 20mg. My MCAS doctor said twice a day and the booklet she gave me says twice a day, but the script she gave me says once a day.

I saw some mild improvement with loratadine, similar to desloratadine and bilastine I think but fexofenadine is useless to me. But the night I started famotidine, it made such a difference to my mental clarity that I’m now sure I have MCAS.

I feel like I’ve read on here that most people take it twice a day but I’m not sure. Also is loratadine usually twice a day? It’s confusing because the doses I see for MCAS are often more than what’s on the box. I’m still early in my MCAS journey so I also haven’t tried much yet.