I have taken elmiron since I was diagnosed in 2004- I took 100mg 3x a day .
You are supposed to take Elimron 1 hr before you eat or 2 hrs after you eat. the first and last dose is OK to follow that rule, but the middle dose is hard to find that time when you haven't eaten within 2 hrs. I went to a new IC provider and she changed the dosing to 200mg 2x a day. So I take it when I first get up - and wait 1 hr before I eat breakfast, and then I take it at night before I go to bed, on an empty stomach.
The other med I take is Attarax (or Hydroxyzine) an antihistamine- I take that at night.
Be sure to look at your diet as well- I find I cant have any caffeine (coffee, tea, soda), chocolate, tomatoes, oranges. And I really stay away from those things that cause me pain, frequency. I can have camomile and mint tea and I have found some other things. I have experimented with trying just one new thing at a time and then I can tell if I can have it in my diet.
It may not work for you, but my urologist told be to take benedryl. She said that somehow the antihistimine helped reduce the spasms (and hence the pain). I didn't like the possible side effects of the other choices so I tried it. Now whenever I feel the spasms starting, I take benedryl at night for a few days. It works for me. maybe ask your doctor about it. Another observation I had was when I drank several carbonated/caffinated drinks, the symptoms worsened dramactically. I stopped drinking sodas, except for one a week and cut out all caffine, except for that first very necessary cup of coffee in the morning and my symptoms have reduced a lot over the years. There may or may not be a link, but I'm not willing to chance it just for a soft drink... good luck.