I have been prescribed this for fibromyalgia. 2 (50mg) tablets three times daily. I have tried not taking them when I didn't feel like I needed to, but its like my body has a hole another plan. I get terribly ill. Chills, fever, anxiety, inability to stay asleep, (even wtth ambien). I'm abusing this drug, but it doesn't alow me to quit without going through hell. My back feels like it's on fire. It's weird.