Yes, fluid retention and weight gain are two common side effects of Lyrica. If Lyrica is causing you that much of a problem, I would definitely talk to your doctor about it.
Have you tried Cymbalta or Savella yet? If none of the medications approved for fibromyalgia work for you, there are still a lot of things that can be prescribed off-label that you might try. Here is an article about all the different meds used for FM: Medications Prescribed for Fibromyalgia
You asked about Topamax. Personally, I wouldn't touch Topamax. It has some really serious potential side effects. Here is a link to a page on our Migraine site that has quite a few articles about Topamax. If you'll scroll through the list, you'll see a number of warnings about possible side effects: Topamax
Of course, you and your doctor will have to make the final decision on that, but I want to make sure you understand the risks if you're thinking about it.
I hope you can find something that will help you without such unpleasant side effects.
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