you can use ice, heat, alternate
Tylenol and Advil, rest, hot showers/baths,
and take the Zanaflex when you are home since that won't matter if it makes you drowsy.
I just think that if you go to the ER and they know you are a chronic pain management...they aren't going to do much for you and then it's going to look bad on your record with this new Dr. you are going to see.
Obviously your choice...just sharing my thoughts...