Some medications can CAUSE them as a side effect so, while not trying to pry, it would be helpful to know what you ARE on - but your doctor would be the BEST person for that, not me. On your next visit, bring EVERY SINGLE THING YOU TAKE WITH YOU. Bring the actual bottles. If you take an over the counter multi-vitamin once a day, bring the bottle. Trust me! (This saved my life once - NOT JOKING!)
Now, on the other end of the scale, I do have a tremor. It is always there. It always has been. Sometimes, it almost seems like it's not. And sometimes, it's so bad that I cannot write. I have found that for me, my pattern/trigger is stress - Pretty much like everything else with Fibro. The more stressed or anxious I am, the worse my tremor is. The last time I check the 'symptoms list' for Fibro, tremors wasn't on it - but when I was originally diagnosed, "Chronic, widespread pain" was pretty much the ONLY symptom. Years later, all these unexplained 'symptoms' I've had FOREVER slowly get added, one by one, to the list of Fibro 'symptoms'.
As for flexeril, I know that everyone is different AND... Please NOTE:
**my body has a tendency to react very oddly and unusually to chemicals - reactions that MOST PEOPLE DO NOT HAVE.... but, I cannot take flexeril. It makes my muscles crawl... it's absolutely horrible. I can't sit still. I want to claw the muscles in my arms, just under the skin, right out to make them stop twitching and jumping and... UGH. I can't stand it.
So, think about when the twitching started and think about "Is it worse after taking flexeril?" And like I said, that may just be ME because I have a family member who takes it and it works like a CHARM for them... but maybe it just isn't a good drug for people with Fibro?
The BEST thing to do is talk to your physician. I have not found ANY pain medications that A.) Make ANY Fibro Pain Go Away or even lessen. I'm sorry. Good luck. I hope you have better luck with that. All I find is that it's good for dulling the senses and, if I'm lucky, maybe I can pass out asleep for a while. Usually, when I wake up, I'm not hurting anymore or I hurt less. My personal assumption on this is that it also affects the neurons and makes them 'reset' so they're no longer sending the mixed messages of 'pain pain pain!' to the brain - but that's just what I, personally, think happens. However, My physician DID put me on a Beta-blocker for the tremors when they were really bad at one time. The trade off is that it makes you pretty tired and sluggish.
I wish you the best of luck.
Best Wishes,
Alix