@seriouslynonames yes famotidine is prescription only. I discussed it with a gastro consultant as I'd had an endoscopy/colonoscopy in July and then had a follow up outpatients appt in early December...I had also previously tried omeprazole in April/May which I think made things worse.
So for me it was in light of having tried omeprazole, not tolerating it well, and talking a distracted gastro consultant into saying yes well perhaps. I then told the GP the gastro has recommended it.
They are only giving me one month at a time which I suspect is due to the shortages and because they may not want me on it long term. But it has transformed my chest pain. I do still get short of breath if I haven't been eating lower histamine food...but I think it helps.
And yes, I don't think the GP will know much about MCAS...but perhaps if you describe it as suspected histamine intolerance based on the foods you eat and you've read online that this drug can help?