Duloxetine
"This is my 5th day on 20 mg (lowest dose - 1 pill per day) Cymbalta for fibromyalgia.  The first 3 days were tough.  My pain would subside during the day, but return almost fully at night. I did not sleep for the first three nights on this medicine. I was also very jittery beginning on day 2. By day 4 most of these side effects subsided and I've been pain free for 48 hours now. I was prescribed 5mg of Ambien to help with the sleep issue. I feel great and energetic for the first time in months. I am thrilled that the lowest dose worked for me."