I had costo 3 times last year. It's common among people like us with fibro to get it. I found that putting on a heating pad really helped. Naproxen is what doctors usually give patients as well as other anti inflammatory meds.
Here's a website that talks about fibro and costo

http://chronicfatigue.about.com/od/whyfmscfsare...

Hope you feel better soon.

I too suffer badly from costohordritis have done for a long time now the pain on too of the fibrl is terrible its like having a heart attack at times. I ve tried hot cold flannels switching from 1 to the next, different pain meds..at the moment I m on amtripiline 50mg along with diazepam 5/10mg for the muscle spams CO codamol 30/500 and servadol 20mg all spaced throughout the day. All honestly I haven't gotten any relief even the hottest showers are a quick fix and the water hitting my chest wall and sterum is unreal pain wise. I cannot take anti inflammatory meds as I have an ulcer and pass blood constantly from my back end if I even have 1.. I find certain foods set if off as well ..I feel ur pain and I really do hope u get some sort of relief depending on the severity of your costohordritis mine started as a fractured rib and spread from there...let me know how you get on in the mean time soft healing hugs xx