I think you are refering to cromolyn sodium (gastcrom).  I am a shocker and a leaker.  When I started cromolyn I was extremely sensitive to everything. I like to explain it as pouring water into a fish bowl.  It kinda mixes things up for awhile...for me it was a week. I was anaphilaxing over everything...meaning my throat would swell. This was my normal though-that may be important.  You name it I had a problem with it food, environment etc. I spent most of the week in my "safe" room with a giant air cleaner and I was mostly in bed because I was so sick.
I have been on it about 3 to for months and would say it has been the best thing I could take. It has really helped me.
Sometimes if my bucket is full and I take my cromolyn I can feel my throat swell slightly. But keep in mind throat swelling is normal for me.
I know some people can not tollerate it.  I felt I had no choice but to get through the initial horrible side effects and get on the benefits.
One thing I also want to mention, I don't know what your probems are but cromolyn will not heal you, it just helps control your symptoms.  I wanted to cry the day the Dr. laid this one on me!
I have a lot more flexability in where I go and what I can eat, but I still cant go certain places and if I eat certain foods I will still go into anaphilaxis.  Got to know the boundries and respect them.
good luck!
Pam

It was a long week!  I think that "leakers" are always leaking symptoms, where a "shocker" will go into anaphilaxis with their symptoms. So I think the throat swelling is more of a shocker reaction.
I was on three doses for a month or so.  Once I went up to the 4th dose a day, I was reactive again. But the meds have really helped me!
Good luck!
Pam