Hi Rosie, I take Ketotifen for MCAS, I was prescribed 1 mg a day, at night. The usual dose for MCAS is 2 mg a day, 1 at night, one am.
It is EXTREMELY sedating so do be careful. Some people, like me never lose the sedating effect, others like Ginger could take larger doses. I started with 1/4 mg at night. It took me quite a few months to work up to 1/2mg, now 18 months in I am on 3/4 at night, the other 1/4 I take in the morning. It still has a sedating effect on me, but not as bad as before.
Like most meds for MCAS it can take a while before you see improvements - sometimes many months. If it hasn't helped symptoms after say 3-6 months then I would say there is no point continuing.
I also wanted to say that I have had an asthma like illness all my life - diagnosed in childhood as exercise induced asthma. Never had an asthma 'attack' in my life, apart from when I was 5 and was exposed to bonfire smoke. Over the years I have numerous lung infections, bronchitis etc, often chronically. 9 years ago I had pneumonia and the respiratory consultant got whiff of my CFS diagnosis and started telling me I didn't have asthma, then that it was all in my head, then that I had never had 'infections'. It got quite nasty at one point. Anyway, the point was that my asthma testing was all normal, even during an acute episode where I could barely breathe for over three months and had to just sit up in a chair or in bed and was in a terrible state. In the end I had to take steroids which didn't help as well as would have been expected, but they helped a little. The consultant continued to say there was nothing wrong with me and investigated me for faulty breathing - which I was proven not to have.
When I saw an MCAS Dr, who also happened to be a lead clinician in asthma he said that MCAS could cause all these breathing problems, even down to seemingly having episodes f infections. He said it wasn't true asthma, but it was airway inflammation. Since being on ketotifen I have been able to gradually reduce my asthma meds, and unless exposed to chemicals or smoke have not had ANY breathing issues at all, which is wonderful. I am also not reacting as much to smoke, food cooking or perfume with breathing issues as I used to.