ibromyalgia
"I was started on 300mg at night for a week, then 600mg, up to 1800mg at night.
I loved in the first week and a half  (it erased most of my pain and my anxiety!) but then got headaches from the 600mg dosage. 
I stopped for a week then began again with 100mg in the morning, 100mg in the afternoon and sometimes 100mg at night. It works! A lot less pain, a lot less anxiety and my negative thoughts seemed to have mostly disappeared. I exercise, work, like normal. I recommend this medicine highly, but start slow. I like taking it mid day when my pain starts to kick in, taking a huge dosage at night makes me groggy in the morning."